I tend to agree with earlpearl, but would also take it further.
PPC isn't rocket science.
Well it's not, sure, but it is a little more complicated than what your average punter is capable of. I think chosing the keywords isn't the part that is rocket science so why bother hiding them?
You write your campaign and Google AdWords will tell you what keywords to bid on basically. The keyword selector tool will do that and it pulls keyword from your site. Also, for a lot of businesses there isn't much choice in keywords. If I sell cars there is only so many combinations of "buy car", "buy cars" that I can come up with and there are only so many terms that people looking to buy a car will type in.
Probably the 'art' of it all is making all the components work well together. So your ad copy matches the keywords, knowing which keywords to put with which adgroup, optimising the landing page, monitoring and removing bad performing keywords and adgroups and making changes to the campaign based on data from analytics and knowing how AdWords works to get the most out of it. That is the real work and the stuff that the client won't see but will make your campaign perform better than if they were to take the same amount of money and bid on the same keywords and probably not get as many clicks or sales.