Hey there Muffin Man.
First things first... on the info bar to the left of your screen you will see a link that says Spotlight Home. Head on over to the main Ibiza Spotlight website (to which these forums belong) and read it. All of it. It will answer a huge number of questions for you - there are descriptions of the main resort areas, info on the top clubs and which parties they hold, etc.
Best time to go depends on what you want to do, but a lot of us around here prefer mid-June (opening party eason) and mid/late September (closing party season). The weather is better in June, to be honest (less rain) but both periods are fun.
I think an ideal trip is 2 weeks but if you have to err on the conservative side then 10-12 days will do you fine. A week never seems like enough, and you're traveling quite a ways so if your budget can handle it then 2 weeks gives you time to party, relax, explore, dine and swim all around the island.
Anyway, have a look at the main site, do a little search on questions that come up once you've read it, then come back to this thread with some more specific queries and we'll try to help
