Carmen,
There are really 3 steps in the process. A ripping program (such as EAC) can do all three, but you should understand that there are 3 separate steps, and it can get a bit more complicated than you might think.
1. Ripping. (Getting the audio data from the CD to a file on your hard drive).
2. Encoding. You can set-up the LAME MP3 encoder to work automatically with EAC, but for legal reasons you have to download it separately.
3. Tagging. Embedding the title, artist, etc. information into the file so that it can be read by the player software. EAC can automatically download the information from
CDDB and automatically tag the files. But, sometimes you'll need to edit or "clean-up" the tags, or perhaps you want to embed album artwork. You can use your player software or you can use special-purpose tag editing software. (I use Winamp as a software player, and I use its built-in tag editor.)
Encoding is probably the trickiest part, because you have to make choices that affect audio quality... As you may know, MP3 is lossy compression (as are most compressed audio & video formats). Data is thrown-away during compression, and there is a trade-off between quality and file size. So, there's lots of discussion here about bitrate (which is related to file size*), audio quality, and ABX testing (listening tests).
If your player has plenty of memory (or if it has a hard drive) you can just choose a high bitrate (high quality) and don't worry about it.
You get the best results (best quality for a given file size) with
variable bitrate. With variable bitrate, you choose the "quality" level, and the encoder analyzes the program material and adjusts the bitrate moment-by-moment... So you don't know the exact-average bitrate (or file size) in advance.
* If you know the bitrate and the playing time, you can estimate file size:
File Size in MB = (Bitrate in kbps x Playing Time in minutes) / 140