There is a long list of tools which can be useful once you decide that polymer clay is for you – however you can get by for starters without buying any tools, and I would encourage you to do so.
A smooth surface such as glass, perspex or a tile – even a sheet of baking paper would do at a pinch. You’ll need a sharp knife – one from your local supermarket will do. To roll the clay into sheets, a pasta machine which is dedicated to polymer clay is great (remember, don’t use it afterwards for pasta) , but if you don’t have one to dedicate to polymer clay, you can use a straight sided glass or a PVC plumbing pipe, to roll the clay. You can also buy clear acrylic rollers for this purpose for about $15. Some rubbing alcohol and an old towel can be useful to clean your tools.
Which brand? It doesn’t really matter. I usually use Kato clay, but if you are starting out I would suggest one of the softer clays such as Sculpey or Premo. Condition about ½ a piece of clay. Start with your lightest color first, and roll a sausage, then fold it back on itself, twist and roll again. Even if the clay is soft, you still need to condition it a little or it will be brittle when baked.
Now you might like to try to make a jelly roll or a flower cane.