Hey!
Someone newer to here than me YAY!
Seriously though welcome, and hope to see you around in-game
As for creating a character with a story in mind or working your actions on your current character into an RP character I would be inclined to say the latter. It might be more difficult to explain some of your actions ICly over the past year but it can be an enjoyable challenge I would imagine. Though again I see nothing wrong with creating a character with a specific idea/nature in mind either - so in other words I am no help at all. XD
As for the bio some people are brief and just do a paragraph describing them, some people use the CONCORD DED Record template lurking around on this site (EDIT: here's the link
http://backstage.eve-inspiracy.com/index.php?topic=960.0), others just throw up a link to their profile on the wiki, some do a combination of both - so a matter of taste
But things I would say are always handy to have in it: Name (obviously), Titles, Appearance (if different to your profile pic), and personally I like to put in a little OOC caveat saying that if I am contacted in game be aware I will treat it as an IC contact unless you tell me not too. But of course that's just me.
Alright shutting up now.
o/