Then I would recommend that you get Garage Band (Purchased with iLife for $79.00)
http://store.apple.com/us/product/MB966Z/A/iLife-09?fnode=MTY1NDAzOA&mco=MTM3NDc5MjUFastTrack ($99.95) - is a great audio interface that can take standard microphones so that you can upgrade to a higher quality mic later if the need arises.
http://store.apple.com/us/product/TB084LL/A?fnode=MTY1NDA3MA&mco=MTA4NDQwNDcAnd pickup a good Mic Like a Sure SM58 ($99.00) from any music store like SamAsh
Total Cost - $279.00
Or you can skip the FastTrack and Mic and just get a direct USB Mic like the BlueMicrophones Yeti ($149.95)
http://store.apple.com/us/product/TY115ZM/A?fnode=MTY1NDA3MA&mco=MTYxMTI1MzQTotal Cost Option 2 - $230.00
If you want a little more advanced features for mixing audio you can use Logic Express which will increase either cost by $120
Or even More Advanced - Logic Studio - which would probably satisfy your needs for a couple of years until you really want to go pro.
Logic Studio is $499 - increasing the overall cost by $420
Why these products you ask?
Garage Band - pure simplicity and ease of use - install it and just follow the easy to understand visual controls - but I've still mixed multitrack recordings and created great quality mix downs with it even though it's not a Pro Level tool.
Logic - allows for plug ins and has the ability to control consoles and some midi instruments - but the learning curve is much larger if you aren't familiar with audio mixing consoles and effects patches, plug-ins and external decks etc...
Log Pro - Very widely used - probably the next best thing to investing $10,000 and up on a full blown Pro Tools rig
FastTrack and Mic - just allows for a mixture of instruments/external decks/microphones so it gives you a little versatility
BlueMicrophones Yeti - Like Garage Band in it's simplicity - just plug it in - launch Garage Band and start producing - For $230 the combination of this mic and Garage Band couldn't get any more simplified and easy to use.
My optimal Choice if I was recommending to a friend that shared the same information you have shared with us - would be to purchase the Garage Band - FastTrack and a Sure SM 58 microphone - Total Cost - $279.00
This is the perfect combination of simplicity and versatility.
I've even recorded a live piano session just using my laptop / FastTrack / SM 58 combination through Garage Band and it sounds like a professional recording session.
Good Luck!
