go to a bunch of electronics stores and listen to as many speakers as possible...do the same for decks/subs/amps

audio preference is very subjective, and just because someone says a certain speaker sounds good, does not mean it will sound good to you

after you've found the gear you like, you can then shop for it online and get it cheaper that way...just never buy an audio product without demoing it first

with regards to subs, if you're not looking for major bass and you just want something that will handle the lows so you can properly cross over the mids, a single 10" or 12" DVC sub in a sealed box would suffice...i'd go with 10" if you prefer pop/rock and 12" if you like rap...10" will give you cleaner bass, while 12" will allow more extension eg deeper bass response

feel free to pm me if you have any more questions