Keep your eyes on ebay for some sort of an am compliance processor. Inovonics made all kinds on them, the 222 which is basically just a limiter and NRSC filter. Their 230 I think was a 8 band mono compressor/limiter with AGC and filtering, can be made to sound very dense and loud. I know a lot of the euro's use Behringer multidynes and ultramizers, but I've never played with one that I could get to sounding good.
If your state-side, look at rat-shack for a 4 channel mixer. You can also pick these up from amazon from people like pyle pro (I know, I can't take the name seriously either). For mics, Shure SM-58's will do, but need some EQ to sound right. I've been running SM-7's for years and like them alot, but you can find a suitable dynamic mic from amazon or someplace for around $150, less if you watch sales through places like musicians friend or guitar center.
You'll also need either cd players, a computer, or both for song and music bed playback. Everything now is on the computer, I use ZaraRadio for on air assist, but it won't run on Windows 7 or 8, XP is the only stable platform for it. Some nostalgic pirates still use cart machines and turntables, and someday my fixed studio will have both.
If you plan on taking phone calls, you'll need a hybrid to get the audio into and out of the phone line.
There are bluetooth ones now that allow you to use a free redirect number to a prepaid cell, and thus get around the liability of having a land line.
A decent pair of speakers and an amp for studio monitors.
Lots more, I sure, but that's the basics.
Hope that helps!
+-RH