Here is my tips on what to get at the start:
To the point version:
List of thing to get a start:
Healing:
Clarity (50): 100 Mana over 30 seconds. Stop healing if hurt.
Tango (90): 3 charge healing item, eat a tree and heal 115 HP over 16 seconds.
Healing Salve (100): 400 HP over 10 Seconds. Stop healing if hurt.
Stats:
Iron Branches (53): +1 to all stats [19 HP, 13 Mana]
Gauntlets of Strength (150): +3 Strength [47 HP]
Slippers of Agility (150): +3 Agility
Mantle of Intelligence (150): + 3 Intelligence [39 Mana]
Circlet (185): +2 To all Stats [38HP, 26 Mana]
Other:
Animal Courier (170): Makes a Courier who can transport items. Can be used by entire team.
Ring of Protection (175): +2 Armor
Observer Ward (200): Gives sight of a 1600 area.
Quelling Blade (225): For Melee Characters, gives 32% more damage to creeps. Good for Last Hitting.
Stout Shield (250): Has 60% chance Damage Block. Will Block 20 Melee Damage, 10 Range Damage.
How to spend your money:
Buy 1 "Other" item at Max. Your team needs a Courier, Wards help, the other 3 may help you in lane.
Buy 150 - 300 in Stat items. Try to go for Iron Branches before the 150 Gold Stat items.
Buy 200 - 300 in Healing Items. Pick up at least a Tango, but you should have both a Tango and a Healing Salve. Grab some Clarity Potions if you think you will be using a lot of spells.
You can save some money for more expensive items, but please don't some thing like "I will not buy anything so I can get a early Ring of Health"
Long Explained Version:
Stat Items:
For Stat based items, you should be looking a Iron Wood Branches, Circlets, Gauntlets of Strength, Slippers of Agility, and sometimes Mantle of Intelligence. Most of the time, you want to grab simply 3 or 4 Iron Wood Branches, since they give a Total of 3 Stat Points for 53 gold, while the Gauntlet/Slippers/Mantel give 3 stat points in one stat for 150 gold. For a support, a common set up to get is 3 Iron Branches, and Healing Items/Support items. For the roles between hard support and hard carry, you tend to be best off grabbing Iron Branches and Gauntlets of Strength. If you are an Agi Carry, grabbing Iron Branches and Slippers of Agility are usually the best bet. Mantle of Intel is usually only good on Int Based Gankers, and even then on a few characters really should bother picking up the Null Talisman they build into.
Do Not start with the 450 gold stat items, which are Belt of Strength, Boots of Elvenskin, and Robe of the Magi. They only give 6 Stat points, so you are better off just grabbing 2 of the 150 gold stat items.
Later game items that common starting items build into:
- Magic Wand: This is 3 Iron Branches, 1 Magic Stick, and a Recipe. The biggest reason to get this is to get your Iron Branches built into 1 item.
- Special note, for Iron Branches, don't feel bad about simply chucking them. If you are a carry or a ganker, you may want to get only a magic stick and not the full magic wand, or just skip it. The Magic Wand is a nice item, but the magic stick has the bulk of the utility already.
- Headdress: Headdress builds into both Mekansm and Pipe of Insight, and also gives a +3 Healing Aura. If you are building a Mekansm, pick this part up first if you are finding your self low on HP Regeneration and are often missing HP. Also gets +2 to all stats.
- Buckler: Builds into Mekansm, Buckler gives +5 Armor, and has an active that gives all near by allies +2 armor. The active costs 10 mana and lasts 25 seconds, so try to activate it when near allies. Each point in Armor effectively gives your 6% more HP when dealing with Auto Attacks. If you are getting a Mekansm, grab this part first if the enemy team has enemies who are able to get a lot of auto attacks off in team battles. Also gives +2 to all stats.
Mekansm is a mid game healing item that is good for supports to pick up (250 Healing every 45 seconds), while Pipe of Insight is an item that puts up an shield on all Nearby allies that soaks up 400 Magic Damage and is a good way to deal with a team with lots of Magic Damage.
- Bracer, one of 3 sister items. Gives +3 Strength, and +3 to all stats, and +3 Damage.
- A Quarky Healing item. When an enemy dies near you, you get a charge in the Urn. The Charge can be put on an ally to heal 400 HP over 10 seconds. It can also be used on enemies to do 150 damage over 8 seconds. The item gives +6 Strength and 50% mana regin too.
- One of 3 sister items, gives +3 Agility, + 3 to all stats, and + 3 Damage.
- Gives Damage Block. 100% for creeps, 60% for Heroes. 20 Damage for Melee, 10 Damage for Ranged. Also gives 6 Agility.
- One of 3 sister items, gives +3 Intelligence, +3 to all stats, and +3 Damage.
Normal Consumables:
There are three items to heal up, Tangos, Healing Salves, and Clarity Potions.
Tango has 3 uses each, and stacks. They heal 115 HP over 16 seconds. You have to wait the entire duration to get the full healing effect, since using ather one within the 16 seconds just restarts the counter. These are best to heal up chip damage you take over time, so that you don't stay with low HP. Tango does not get cancled by taking damage though.
Healing Salves Heal 400 HP over 10 seconds. Best to heal large amounts in a short time. The biggest thing to note, if you get hurt, the healing will stop, so try to stand back while the item is healing. Many Damage over times will stop it from working too, so try not to waste the item because you have a DoT on you. The Item's Healing Stacks with Tango, but not Urn of Shadow's Heal.
Clarity healing 100 mana over 30 seconds. This item will also be canceled if you get hit while it is active, but due to the huge duration, you tend to want to try and get last hits still when it is up, so exercise caution. Most range enemies will go out of their way to hit you and cancel it though, so take caution and use that bit to your advantage. Also, try to remember if you have the item on you when chasing an enemy and you are out of mana.
Support Consumables:
The two big ones at that start of the game are the Animal Courier, and the Observer Ward. The Courier takes the highest Priority, someone needs to buy one at all costs. Being able to get items when out in the filed is very very important. The other one, Observer Ward, allows you to keep vision on key spots. You really should have this, but its not the end of the world if you don't. But really, get them.
Support Consumables to get in the early game, but often not the start:
In the first 5 minutes or so, someone on the team should upgrade the Courier to a Flying Courier, which makes it go faster and cuts down on the time it takes to get items.
Situational items for the early game to get are the two Anti-invisibility Consumables, Sentry Wards and Dust of Dust of Appearance. Sentry Wards are static objects that last for 3 minutes, and give sight of invisible units. They can be used to easily counter people who can easily go invisible while in lane (Broodmother, Bounty Hunter, Clinkz, Riki, Sand King, Invoker), or when pushing a lane. They can also be used to try and destroy the enemy wards.
Dust of Appearance is an item that makes all invisible units in a 1050 range be visible for seconds. Best used to counter Shadow Blade, it can also let you chase after other units who turn invisabile. Great for chasing down an Invisible Invoker or Riki.
Don't Stop Buying Observer Wards after the early game, make sure the team keeps getting them all throughout the game, and keep items to counter invisibility the entire game if needed.
"Other Stuff":
These are items that you will often get at the start of the game to help you lane, or do other stuff. They are Ring of Protection, Quelling Blade, and Stout Shield.
Ring of Protection is a little +2 Armor Ring. Nothing to great, but the reason you get it at the start is that you can't buy it in the side shop, and it builds into two items you may want to get in the early game (Which the part of can be found in the side shop), Ring of Basilius and Tranquil Boots.
Quelling Blade is an item to grab on Melee Characters to make last hitting creep easier. It give you 32% bonus when attacking any unit who ins't a Hero. It technically works on Ranged characters, but is very rarely worth it (12% for range). Also, Quelling Blade is able to cut though trees, a useful little skill that can get you in/out of odd spots.
Stout Shield is an item with a chance of damage block. It has a 60% chance to block damage, 20 from Melee, and 10 from Range. The big reason to get it is to reduce damage if you suddenly get agro from all the creeps, but the damage block do add up with ranged characters. The Stout Shield also build into two other shields, Poor Man's Shield and Vanguard. Poor Man's Shield is a Stout Shield with +6 Agility, and 100% chance block for creep damage (Still 60% for heroes), while Vanguard has a 70% chance to block 40 Melee/20 Physical, plus it gives 250 HP and 6 HP/Second.