http://www.bungie.net/en/Legend/2/4611686018428392362/2305843009215348711
Out of the 103 raids I have been a part of on my hunter alone, I have only completed 30 full raids.
Lots of oracles and forward runs.
Lots of hard mode Atheon runs.
Lots of hard mode gate keeper plays.
2 flawless raider completions, out of 24 runs.
Some things I will say to people doing the raid for the first time;
Listen to your teammates, and be ready to take a role you may feel out of place at.
Doing the raid for the first time, it is nice to do it blind for the feeling of discovery, but if you want to complete the raid in under 4 hours, you might want to listen to someone that has experience.
Most raids done by the seasoned take less than an
hour on normal, and just over an hour on hard.
This should be your indication that your team may be suffering from a deficiency.
Weapons used should be legendary, fully leveled, with void being top priority in most secondary/heavy weapons selections.
Using Rare weapons for a normal raid, although possible, also leads to your character being a liability, not doing enough damage in a timely manner.
Rare weapons are unacceptable for hard raids.
Partially upgraded, or non-upgraded legendaries/exotics are not acceptable.
Your gear should be leveled to the highest you can muster.
High armor ratings make you less likely to go down from a stray hob goblin/pretorian shot, so make sure you are as close to 28 as you can get for normal, and as close to 30 for hard.
Q:
Is it possible to do a normal raid with all 26's?
A:
Sure!
Q:
Will I have fun?
A:
If your idea of fun means dying a lot, and being one shotted on many cases, then sure. If that doesn't sound very fun, then no, you will be pretty annoyed, and start bickering/blaming for problems that just happen being low level.
If you are having issues with a player, make sure to check the gear they are using to look for possible solutions.
You yourself may be the issue, and require adjusting. Be understanding, people are helping eachother do the raid, and if one person is slowing down progress, it slows everyone down.
Adjusting could mean changing weapons, or putting a player in another location to help protect them better.
We all like to think we know a few things about the game, so sometimes experienced raiders will bicker over strategy.
It is important to be open, but ego's should be tempered for the greater good of the many.
I have seen many groups crumble under pressures of butting ideas, egos, and strategies.
Sometimes its ok to let someone else take control.
Sometimes you must take control.
Be willing, be helpful, have fun.
It gets pretty hectic,
make sure you understand your left from right. 
