Lets get down to business already, I hate writing long introductions. What will you need today? All you'll need to do is select your favorite MP3 codec and install it.

LAME LAME seems to be the most popular and widely believed to be the best on the market.
FranHofer Radium FranHofer Radium is the fastest and not very good for all of the quality freaks.
OGG Vorbis
BladeEnc BladeEnc seems to be better than LAME at higher quality settings.

Now that you have a codec installed we'll move onto the next step. You'll need to add this to your registry.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer\Settings\MP3Encoding]
"LowRate"=dword:0000dac0
"MediumRate"=dword:0001f400
"MediumHighRate"=dword:0003e800
"HighRate"=dword:0004e200

If you don't know what to do with this then here's a simple .reg file for you to import into your registry. MP3.reg

After using this registry setting you'll want to start Media Player and go to tools --> Options --> Copy Music Tab. You'll now see something similar to the image below. 128Kbps is very commonly distributed around the internet but for anybody with a decent sound system this quality is nowhere near what you want! 256Kbps is a decent balance of quality and storage space, but there's also 320Kbps available if you follow these instructions.

If you want to further customize these settings then obviously the registry values are hexadecimal numbers. For example 0004e200 is 320000 AKA 320K. Now that you know this then simply make the calculations to adjust the settings to whatever you would like!