There is a great article in the Super Street parts catalog, on the shelf now, which can explain alignment stuff really well.
And yes if you do anything with the suspension you NEED to get an alignment. If a person must skimp on thier car, I hope they just dont drive it until they can get it right. That's my attitude.
Yeah an alignment will cost you a little, but not nearly as much as it would if you fly off a damn bridge or something.