There are quite a few different programs you can use. wings3d is free and seems quite popular, available at http://www.wings3d.com. Some people use 3dsmax but I find that difficult to use and it is very expensive. Lightwave is another expensive one. Cinema4d is used by some and so is truespace. You would be better to download demos of the programs (if they are available) and try them out to see which one you prefer yourself.