Claying is a must whenever you are going to do anything with the paint, follow three steps always when you are going for car detailing. Washing your car with fresh water with a good car shampoo with two buckets preferably with a dust collector, using wash mitts, Drying your car using with a water magnet or heavier micro fiber cloth. Claying the surface by proper kneading and folding of the clay bar, and after claying preferably another wash with fresh water and shampoo or if thats too much of a hassle atleast a good through rinse. After you have done that apply the wax or the polish or whatever you feel like. One thing to make sure is that if you polish your car make sure to apply wax over in the same session.
For weekly wash, claying isnt necessary, just using two bucket method with a good car shampoo and materials and a wax coat after that would keep your car's paint in good condition. As for supplies I will recommend that you contact Ahmed Yar bhai, he imports quality products like nanoskin etc. He might be able to give you a great deal on a introductory package hopefully. I atleast always refer to him when I need advice on detailing.