Brand: more experienced cake people will have more specific advice, but I've been happy with Orchard (the supermarket one) and Bakels white fondants. Haven't tried any others except the Fondarific chocolate fondant, which is nice to work with but I think it has a horrid aftertaste.
Colour: don't use liquid food colouring, except if you're only using a tiny bit to make very pale pastels. The liquid ruins the consistency of the fondant. Use concentrated gel colours (from cake decorating stores, Spotlight or I've also seen a smaller range in King of Knives).
Buy white? Depends what colour/s you need. For red and black, definitely buy pre-coloured fondant. Cake decorating stores also sell fondant in some other colours - personal choice based on what you need it for, time available, the number of colours you need, budget (white is usually cheaper), etc.
Where to buy? You can get pretty much everything you need online, but it may be useful for you to go into a specialty cake decorating store for the fondant and colours - the staff are usually happy to give useful advice about what you'll need.
Tools: Personally, I buy on ebay. Much much cheaper buying from overseas stores for things like specialty cutters.
At a minimum you'll need a suitable working surface (silicone pastry mat if your kitchen benchtop isn't smooth enough) and a large rolling pin. Other tools depend on what kind of decorating you want to do. I buy a few little bits and pieces every time I decorate a cake (max 3x a year) and have a nice little collection now.
Also, make friends with other cake hobbyists
. I've borrowed cake tins and fondant tools from friends and am happy to lend in return. It means you don't have to spend as much to have access to the same equipment.
- Start with round cakes. I started with square cakes and the corners were very difficult to get right.
- Microwave fondant for a few seconds to soften it. Easier to work with and if you have a stand mixer with a strong motor, you can put the softened fondant in there and use the dough hook to mix colour through it.