Hi,
first of all, you should really read some basics about recording, that will make many things clearer for you:
http://www.google.cz/search?sourceid=chrome&ie=UTF-8&q=home+recording+basicsIf you are at least little serious about recording, you should get external soundcard. The built in mic inputs in notebooks do work, and they shouldn't sound like total crap (I suppose you are doing something wrong when trying to use them as input, maybe you have the input level too "hot"?), but any external sound card will work better.
There's another reason to buy external soundcard - latency
http://www.google.cz/search?aq=f&sourceid=chrome&ie=UTF-8&q=soundcard+latency#hl=cs&sa=X&ei=xrkXTeXSFcmX8QPOlamEBw&ved=0CBYQBSgA&q=sound+card+latency&spell=1&fp=bfafa08e53c2f78a. That means, if you would like to do multitrack recording one instrument after another, you need soundcard that is able to play and record at once with the lowest latency possible, so the instruments do play at once. This is impossible with internal soundcard, where the latency is big and so recording one instrument on the top of another is impossible.
There are many souncards out there, it depenends mainly on how many mic inputs you need. You can have a look here:
http://pro-audio.musiciansfriend.com/co ... interfaces for some overview of what hardware is out there, or check any other music eshop.
If you are on a budget, I can recommend the M-Audio products, they work well and offer the best value for the money spent. If your intention is do some homerecording, you won't need more, there's always some basic music-production software built in.
Just to be clear, as usually, if you won't a pro gear, it will cost much more, but for a normal non-prorecording use, you don't need to spent thousands dollars...
Btw., I got this "soundcard" -
http://usa.yamaha.com/products/music-pr ... mode=model