Is there any internet resource for character ideas, personality ideas, backround ideas, etc.?
And what about hints and help for staying in character and having a reasonable goal/motivation?
Abulafia is a great resource for random generation of a variety of things. Have a search for "concept", "personality", "trait", "quirk" or any number of other keywords that might turn up something useful to inspire you. A couple of pages I might point you to that may have something worth stealing and making your own:
Masks is a great book, should you or anyone else feel like buying something appropriate. It has many characters for different genres, themes and situtations. There's plenty of information to crib from and roleplaying tips to use. Little quirks in speech and action make characters memorable, though some are only suitable for short-term use and would be grating on peoples nerves if used by a player character.
It may be obvious to you and many others here, I'll mention this for anyone new to roleplaying. Making secret things about your characters is
not a wise thing to do and generally doesn't work well in actual play. It usually makes both you and your character seem guarded and defensive, not mysterious and interesting like you'd hoped. If your character has a secret, make sure to tell the other
players what it is, they may be able to help you build on it or create something of their own to link up with it in some manner. Also, by telling other players, their characters can "accidentally" bring up a topic or construct a situation related to it and make things interesting.
While most games as written don't put written character backgrounds and concepts into play in their entirety, very little in most cases, it does help to use these to get inside your own characters head and know what possible reactions they could have in any given situation. Feel free to write a 3 page account of your characters life; don't expect anyone else to read it, but it will be immensely useful to you in envisioning this character, how they think, react, behave and interact with others.
Look at the background you've created and make some bullet points on the most important aspects, things that will frequently come up during play and help you think on your feet. You may find yourself making little revisions to the history as you go, realising that the events in the characters life changes who they are and what they're like, as those changes impact what they do in the future. Eventually, you'll be able to see what the character believes, what's important to them and what it is that drives them (the latter two could be the same or completely different).
These aspects expanded into succinct points will make it so much easier to play your character because you'll have motivation based on important life events. At any point you should be able to look down at these points and come up with a character-believable response to almost any situation. They'll provide guidance without being restrictive, allowing you a range of choices within the scope you have created. If you feel that in most instances, based on these points you've made, if anyone asks "why did you/your character do that?" and you have a justifiable answer in most cases, you've done well.
This is the way I do things and I hope I have articulated it well enough. It's an enjoyable process that I find it works well in practise, especially if you're able to bounce a few ideas off someone to see if it makes sense.