Wow, I can't believe no one has mentioned the Useful Links...
Hey tomveg, welcome to Head-Fi, and sorry about your wallet (don't worry, you'll know why we say that soon enough). If you look at the top of every forum's first page, you'll see a list of links that looks like this:
What you'll want to do is look at the three links in the green oval. The first one you should start with is "
A Hopefully Helpful Headphone Buying Guide For Newbies By Boomana" since it not only gives you a starting point, but also some helpful advice on how to get the most from your time here at Head-Fi.
Then, as you read through (and post in) the forums, you'll want to have the "
Glossary of Terms" and "
Describing Sound - A Glossary" threads open so that you can understand some of the terms we commonly use here. We'll say things like "sibilant' or "PRaT" not because we're trying to be all superior, but because it's easier and faster than typing out "that harsh sound the she sings words with a sss sound" or "pace, rhythm and timing." You'll get used to it soon enough, and be using those terms yourself in no time.
OT: Why are y'all pointing him straight to IEM shootouts and stuff? He didn't mention anything about IEMs in particular, and was just asking for a general starting point. Those are good links, but I'm just sayin' it might be a bit of the deep end too soon...