Although it's good to learn how to make your own gum paste, I don't and I'd bet most pastry chefs don't either. You can buy it through several sources, some sell it premixed ready to use and some sell it as a mix where you add h2o. "Sweet Celebrations" it's a baking catalog and "Wilton" both carry it, they also have alot of interesting tools and cutters.
Often your rolling out the dough to a certain thickness and then using a cookie cutter to get the right shape for you petals. Then you form your flowers from there. So a good place to start is with Wilton, they sell a set of cutters for gum paste (at a reasonable price)and an instruction booklet comes with it.
Small flowers are much easier to make than large ones that require many steps (I'd suggest you start with small ones). Most books teach you to insert wires into your flowers. But you don't have to do that (it's not always easy) until you've gotten more comfortable with the paste. You can use royal icing to apply and finish you flowers. You can check out a cake I posted at webfoodpros.com (look under the post "need help from a wedding cake expert please") where I made small flowers with-out wires and used royal to finish on a wedding cake I did. Looks hard but it turned out to be much easier than I had thought.
You have to take all the warnings about wrapping your dough tightly so it doesn't dry out seriously (especailly when your storing it for a long time). Yet don't panic over constantly covering every tiny piece when your working with a small amount. Usually if you knead it abit it will soften back up.
After your gum paste dries a day or two later, you can paint color onto it. Use powdered food colors with vodka or clear vanilla extract (also from Wilton). Food coloring pastes are tricky to use on gum paste.
As far as books, I'd recommend Wilton as your first introduction. There are tons of great decorating books, Beryl's sells a nice selection. But you don't need to invest as much money on cutters and books as some decorating books would lead you to think.
I agree that for someone getting started, the Wilton set of cutters can't be beat for price. It's still only $20 for all those cutters and the instruction book. If you lose interest, then you're only out $20. The downside is that it's frustrating to work with such poor quality cutters. Their modeling tools also have such annoying seams that even filing couldn't help. If this is something you want ot get into, it's worth it to invest in quality cutters and tools. You get what you pay for.