If you live in a country with Cost-co stores, you can buy nine packs of Bicycle decks, five blue and four red, for a very good price. These are regular decks (not magic trick decks, so skill is involved), but high quallity. You will want a few decks of both colours for effects where the cards change colour. There are such things as trick decks, but don't get these while you are starting out. If I were you, I would buy two books: Royal Road to Card Magic and Scarne on Card tricks. You can get these from
www.penguinmagic.com . Royal Road will teach you the sleights (skills) And a few effects. Scarne on Card Tricks is a great way to start because you need no sleights to perform the effects. It will also teach you other important parts of magic, like patter. If you need any more help, send me a P.M.
Good luck and have fun learning the art of magic!