Jeff,
The most important tool is a torch. Copper work hardens rapidly and must be annealed well and often. The smaller the radius of the bend, the more times it must be annealed. If you are trying to make small radius bends of less than 3 or 4 times the diameter of the tube, you will have to anneal several times. If you are trying to make very small radius bends, then a rod with a groove turned in it that as only slightly wider than the diameter of the tube and as deep as the tube diameter is one way to keep it from collapsing. It is best if the groove has a round bottom, but I seldom do it. Mostly I just cut with a parting tool. You will still need to anneal the tube. It takes little practice, but you will "feel" the tube start to work harden and know you have to anneal it again.
To anneal, heat the tube to a dull red, and then let it cool. You can dip it in water to cool faster if you are in a hurry, but that has no affect on the annealing. After all the bending is done, the oxides that form on the surface of the copper can be removed by dipping in a pickling solution. Lots of different ideas on what to use for pickling and it has been discussed a lot on this forum. I use a 5 percent sulphuric acid as a personal preference, but lots of others use citric acid or a commercial pickle preparation.
Let us know what size tube and what kind of bend and some of us may be able to be more specific in our recommendations.
Gail in NM,USA