-2 turntables. preferably technics 1200s. which are about $450 a piece. i know not cheap but their value is worth it in the long run. you can spin records on cheaper tables but just get technics. trust me.
-needles. get ortofons or stantons or shure. the long skinny ones are more expensive, the ones with the headshells work fine and are a bit cheaper
-mixer. you can spend as much or as little as you want, but just remember that the more you spin, typically the longer it will last. i wouldn't spend less than $300 on a mixer. you don't NEED too many extras on a mixer, just make sure it has 3 way equalizer (bass, mid, treble), and at least two outputs (booth, master)
-headphones. try some on. the new pioneers are real nice, and sony makes good ones too. you'll be spending at least $100 on headphones.
-amp. i just use a 2x100 watt receiver i got for $150 at soundtrack. you want this kind of power but you don't need a full on 5 channel receiver, and you also don't need a prostereo amp....those are more more loud playback at parties and concerts.
-speakers. DUDE YOU NEED !!!!!TWO!!!!! SPEAKERS!!!!! sure you can do it with just one, but considering most electronic music has quite elaborate separation of stereo channels, you need two speakers because music in mono is just lifeless, plus just one speaker isn't loud enough. i use two studio monitors with a 6 inch woofer and they put out surprisingly good bass. cost about $350 for the pair. go with bigger speakers if you want more bass, but you pay a lot more for the same mid/high range sound quality with bigger speakers.
records. either know a good record store close to where you live or find some internet sites. records are the most expensive part unfortunately. i have about 250 or 300 which totals about $3000. ouch. when you first buy records, buy a lot, get different records in the same genre to see what you like most.
this is ''all'' you need to get started. if you want to record, a tape player always works if you're short on budget, or a cd burner will work too, but a computer is the best.
Abba Zabba, you my only friend