The stores online at the bottom of the forum pages are great - and also sponsor the site (So, I'd advise them, MagicBox is my personal site of choice, great reviews, amazing customer service)
Bill changes can be great, but certain moves DO require practice / have a nice little nack to them, its hard to not reveal stuff on here, but your best bet is to decide what magic tricks you want to actually do ... and it'll depend on your skill level too, if its cards, then you NEED to be buying Royal Road To Card Magic, "amazon.co.uk", £5 - £10.
If its coins, then Bobo's coin magic is a great start - amazon.co.uk is your best friend here
Let us know a bit more about what you want to perform and I'm sure you'll be FLOODED with trick ideas
All the best (and welcome to TM if I haven't already said it in your intro)
Dan