They can be good, they take time to learn though, but the amount depends on you. I played around with then for a while, they were a lot of gun. I know GL and Carl have a lot of experience with them as well, and they are very good at exercise programming so they will be able to give you a lot of insight.
I probably rushed into them a lot, and I did have quite a few close calls with almost getting hit with barbells and almost falling over and that sort of thing. But if you ease into them you will be fine.
I did the Oly lifts 2 times a week, but you can do them more often if you want and if it fits in with your program. But lets say you spend 2-3 weeks learning them with light weights + doing heavy front/back/overhead squats and a some heavy pressing and pulling you should hit everything.
You can read this too http://muscleandbrawn.com/forums/art...g-methods.html
If you want to learn them, ontop of good youtube videos and reading online, you can read Tommy Kono's book, "Weightlifting Olympic Style", its a great book. Though the best thing would be coaching from a good coach.