[BillyT]

Jim, generally speaking, the most common bitrates for stereo are as follows, from lowest to highest:

64 96 128 160 192 256 320

The highest available bitrate is 320. The number represents how many kilobits per second are being processed. I don't consider this piece of information essential to know, though.

MP3 files with higher bitrates have the highest sound quality, but they will be larger in size.

MP3 files with lower bitrates will not have the best sound quality, but the files will be smaller.

In almost every case, selecting a bitrate is a judgment call on your part. I personally use 160, however, I have many ripped songs at 128 and some of them sound better than the CD. I never would recommend 64 or 96 they just sound crappy.
Here's a chart that shows how bitrates, sound quality, and file size all relate to each other.

Bitrate Sound Quality File Size (per one minute of sound)

320 ----Highest Quality ---- Largest for MP3 Files
256 ----High Quality ----- Very Large: Over 2.0 MB
192 ----Excellent -------- Larger: Over 1.5 MB
160 ----Very Good -------- Large: 1.5 MB
128 ----Good ------------- Standard: 1 MB
96 ----Fair ------------- Small: 700 KB
64 ----Low --------------Smallest Possible: 400 KB

Here's one more chart. It shows the difference in MP3 file sizes for a song running time of roughly three minutes.

Bitrate ---------------Size of File
320 --------------------7.38 MB
256 --------------------6.73 MB
196 --------------------4.43 MB
160 --------------------3.69 MB
128 --------------------2.95 MB
96 --------------------2.21 MB
64 --------------------1.48 MB

Hopefully, it can give you an idea of how an MP3 file's size depends on bitrates and levels of compression.

Hope that helps.

Have A Happy Digital Day