I used to know how, I think it involved the software Bladeenc and Goldwave (possibly) but that was on an older computer and I need to refamiliarise myself with the software necessary, anyone know how?
You’re best off heading over to download.com, and checking out what they have to offer. Many of the software programs you have to pay for however so it depends on how bad you need one.
I believe in Goldwave you open your .wav
then you go file save as
then there should be 2 pull down menus on the save prompt
the second one you should change from whatever it is to .mp3 format and then hit save.
I think that should work.
If all you want to do is encode wave files then you just need an MP3 encoder. LAME is currently thought to be one of the best and is available, together with a handy GUI (LAME itself needs to be operated from the command line, Razorlame is a graphical frontend for LAME), from this location :
http://www.xs4all.nl/~bn/razorlamepack.exe
The following site explains how to use Razorlame :
http://www.dors.de/razorlame/docs.php
The fact that you mention Goldwave indicates to me that you may wish to “rip” audio tracks as well (convert CD audio —> WAV files). If this is the case, then I suggest you download an application called Exact Audio Copy which can make very accurate audio extractions, free from the “pops” and “clicks” that sometimes feature on tracks ripped from dirty or scratched CDs.
You can get it from here :
http://www.exactaudiocopy.de/eac09b4.exe
Hope this helps, I’m sure others will clarify some of the points I’ve made here.
NinjaMan is right on the mark!
Use the tools he links to. Let’s rid the P2P World of crappy rips!
Also check if that proggie has a normalize feature, that can come in handy as well.
Thanks, once I get the stereo hooked up to our new computer I’ll try out the software suggested. I’m looking to backup my old eighties tapes, I think I’ve lost 5star and Fine Young Cannibals already 
You can obtain the latest released LAME builds from hot.ee/smpman. These are command-line only, so you’ll have to read the USAGE file to figure out what to do. They allow more precise control over the encoding process, however. If you don’t mind losing some control for the ease of a graphical interface, then feel free to use the RazorLAME program NiNjAmAn mentioned.
CDex is a good free program that combines ripping and encoding. It can go CD->WAV, WAV->MP3, or CD->MP3. It includes the LAME MP3 encoder, as well as encoders for a few other formats (e.g. Ogg Vorbis).
another vote for cdex. a great and very easy to use application. plus the LAME encoder is supposedly really solid.
FreeRip is a great little program which rips, encodes and even gets the disc info from the CDDB. Works perfectly and is freeware! Get it here.
musicmatch jukebox will do it (file, convert) but i dont think theres a free/shareware version available
Avoid MusicMatch Jukebox. It produces MP3s of terrible quality, arguably the worst possible (Xing (Audiocatalyst) can make some very bad ones, also). One should NEVER use anything lower quality than the genuine Fraunhauffer Professional MP3 encoder, and of course LAME is best. r3mix.net has comparisons of a number of encoders, including good details on why you should never use MusicMatch.
In short, Musicmatch uses a version of the Fraunhauffer encoder that removes all high frequency sound data, and overall has rather poor sound reproduction.