normally you make em in wav.. and do them as separate hits. you just can record them in using sonar or even a simple wave editor. but as to what you do processing wise, thats up to you .. most sample cd's etc that I use have had processing done on them to make them punchy etc.
well you could use dimension pro if you want kits (or even session drummer) , does involve a bit of text editing..but not tricky.. does support layers.. if you open up a drumkit "sfz" it'll give you pointers of what to do if your new to it.
there is a sonar drum masterclass on youtube that might give you some pointers
there are loads of sources though for cheap samples done in decent studios etc. but you might find the session drummer etc ones useful