I understand that it is much more convenient to keg beer instaed of bottle it. But as far as the process goes, is there a huge difference? Do you still have to prime it in a keg? How long do you have to wait once it is kegged?
You can prime like you would if you were bottling, but you don't have to. You can carb it using CO2. There are two (or more) methods that are commonly practiced. The first, is you figure out how much pressure you need to achieve your desired volume of CO2, set the regulator at that PSI and leave it for a week (or more) and it will carb. The second method is quicker and often called 'force carbing'. Basically you hit the ket with a PSI in the 20-30 range for a few minutes while you roll/shake the keg or overnight. After that you back down to your serving pressure and the beer should be carbed.
The bottling/kegging area has lots of info on this. Each method has it's pros and cons. Priming leaves you with a lot of yeast sediment, the 'set and forget' method takes longer than force carbing, but force carbing doesn't mean the beer will taste 'perfect' and can over carbonate if you're not careful.