I tried creatine in the past and it really didnt agree with me. I suffered from muscle ache the whole 2 weeks I was on it before packing it in. I may had poor quality stuff - it was Holland and Barrets and their gear seems to be considered very poor by anyone seriously into weight training.
I would recommend a good whey protein supplement though as its very useful whether you're training to lose bodyfat or build muscle. I get mine from
myprotein.co.uk - The Leading Online Manufacturer & Supplier of Sports and Nutritional Supplements and recommend the banana, raspberry, chocolate or choc-mint flavours. Strawberry was too sweet for me and unflavoured was just vile. They also do some amazing whey-protein raspberyy flapjacks made from whey and oats, extremely tasty and none of the fat and sugar real flapjack has. I often take one or two of these to shoots with me. If anyone wants to order, use the code MP30835 for 5% off your first order.
I messed around with weights for years before I finally did some research on the net and got my head round the whole diet thing. Once i got the diet right, the weight just flew off and I made very good strength gains. I didnt pack on much muscle as I was training more for losing fat, but i didnt lose any either as people often do when they crash-diet and thats the important thing. You dont need supplements at all, but I did find the whey shakes pretty useful.
hope this helps