^^^all the above posts assume you have ableton. do you? if not and you want a cheaper/free solution just to get started, you can use reaper or audacity.
i will say tho, if you plan on purchasing software, ableton aint a bad way to go.
here are a list of daw/recording software you might want to consider (the main ones, although there are others)
protools (need protools sound card to go with it)
protools m powered (need m powered sound card to go with it)
cubase
ableton/ableton lite (also good for makin beats)
reaper (free)
logic (mac only)
audacity (free, prob not permanant solution)
also, you are eventually going to need an external sound card (better sooner than later), you can temporarily use your computers stock sound card, but you wont get any proper connections or great performance out of it.(fine while you figuring shit out tho) an external sound card will perform better, give you all the connections you need, better sound quality, midi, and monitoring. the words 'sound card' and 'audio interface' or 'firewire interface' or 'AI' are sometimes interchanged (mentioned this so you dont get confused).
if you getting protools you can only use protools sound cards with it (same goes for m powered protools, you can only use mpowered sound cards). all the other software, you can mix and match various sound cards from differant companies. there are 2 routes to go with sound cards, usb, or firewire cards. generallly, the smaller cards use usb and the larger ones with more inputs use firewire. here are some brands to get you started, its difficult to recomend you one cause there are cheap and expensive ones, it would depend on your budget and needs (i.e. do you just want to record mpc, or do you want to record multiple gear, mics, etc.), do you use mac or pc, how much cash you willing to drop, do you plan on sequencing or making beats on computer, or just recording:
m audio
motu
protools
presonous
peep this site and tutorial for more info:
http://tweakheadz.com/soundcards_and_au ... rfaces.htmto record my beats i use reaper and a motu 828 mk3 connected to a dell laptop. (really, i could have gotten a smaller interface, but wanted the mk3 incase i need to record more gear or use the 8 outs on my mpc)
there are 3 mains way you gonna record to your computer (assuming you have an audio interface).
1.record your main outs (stereo outs) of mpc into 2 inputs on your interface as 1 stereo track in your daw (sometimes called 2 tracking).you only need two inputs on your interface to do this (left and right input/channel)
2. multitracking, i.e. record each sound on its own track. to do this you will need multiple outs on mpc and multiple ins on your interface, assign each pad to its own out, and correspond your interface ins to seperate tracks in your daw. your sound card will need multipe ins.
3. multitrack using midi sync, track mute in mpc, and only 2 ins - midi sync your mpc to your daw using midi on your interface, solo each individual track in your mpc, play each track as it is soloed and repeat until you have all tracks recorded into daw. (little more to it than that, but you can figure that shit out)