A good selection of cake pans is crucial, as are decorating bags and a large assortment of decorating tips. If one is planning on using fondant, cutting tools will be needed and if one will be creating gum paste flowers then molds will need to be purchased as well.
There are many sites available to purchase commercial cake decorating supplies such as cake pans, bakewear, rolled fondant and more. The following sites I suggest and would recommend are: www.officedepot.com, www.cooksdream.com and www.shopbakersnook.com
Amazon has a wide range of books on the subject of good cake decorating tips and techniques. One such book they stock is "Fun and Fancy Cake Decorating Tips".
That depends which tool you're talking about. The knife-like one that is used to spread the icing is a spatula. A decorating bag or parchment cone is used to hold and push icing through decorating tips to make designs and shapes. Various other tools are used for smoothing or making lines in icing.
There are many cake decorating classes offered in your local area. Take one of these classes and see if you are really interested in becoming a cake decorator.
You can register for a Wilton Cake Decorating Class online at the website - Wilton. They offer a variety of classes, just click on the one you are interested in and you are well on your way to being enrolled. Tuition and registration fees are listed beside the Decorating Class.
If you are interested in finding information on different cake decorating ideas, there are many websites you can go to. One of the more popular is All Recipes.
For great Christmas cake ideas, one should look on websites such as Hobby Craft. Some decorations one can find are Christmas tree cakes, cakes that look like wrapped gifts and the classic ginger bread house.
Look in a big box craft store--they often have entire sections dedicated to cake decorating--tools, accessories, pans and so on. You can also find cake decorating kits on places like Amazon.com and eBay. They have some great kits that you may not be able to find locally. Craft stores often have really great cake decorating kits. Try places like Michael's or Joanns.
The absolute best place you can find Wilton cake decorating tips at would be the official Wilton website which has a section dedicated solely for this purpose.
Hands
There are many places that offer cake decorating classes. Community centers, craft/hobby stores, community colleges, and culinary institutes. FInd one that suits you.