Ok, I need some help understanding different MP3 encoding modes.

I think I understand bitrate: the higher the better, right?

But what does CBR, VBR, and ABR mean? What is the difference between Stereo, Joint Stereo, and multi-channel?

VBR is variable bit rate. I'm guessing ABR and CBR stand for something along those lines.

You'll probably never need to use higher than 192 kbps. I don't think higher rates are audibly better, and they make the file sizes much larger.

CBR = Constant Bit Rate (Ex: entire song coded at 192 kbs)
ABR = ? (Average Bit Rate?)

Ignoring differences in encoding software, higher does typically mean better. I recommend EAC (Exact Audio Copy - a free download) with a recent version of LAME for decent-sounding MP3s. Standard (or extreme) VBR is probably your best bet, unless you don't mind large files. 192 kbs is too low for my tastes, but seems to be the standard for many. Stay the hell away from Xing. MusicMatch and other widely-known "quickie" programs tend to suck major ass. Good encoding takes time.

What he said. Here's a nice step-by-step guide for EAC/LAME.

ABR is Average bit rate, but I'm not sure what it means. You might find something here.

EAC/LAME is awesome. I'm sorta in the process of re-ripping everything this way, but I've been lazy as of late.

EAC/LAME

to quote the illustrious Blackstreet

"no diggity, no doubt"