I'm sure that you've seen it already, but John's care sheet for toads (Toad Basic Care) is a great summary. I would be careful with the heat lamp - American toads are temperate zone animals, and do just fine at room temperature (70 - 80 degrees). Mine are kept at mid-70s with a dim fluorescent tube.

As others have already commented, supplementation with vitamins and calcium is advisable - I gut-load my crickets with Repashy insect gutload and dust with Repashy Plus ICB once a week. Other people have different schemes that are fine too. I also recommend a wide variety of (safe) prey if at all possible. I use Dubia roaches, crickets, butterworms, silkworms, hornworms, "phoenix" worms, isopods and the very occasional pinkie (as a treat for the big guys), all of which are available online as captive-bred stocks.

If your toads are juveniles, you need to be especially diligent about supplementation to ensure that the animals are receiving enough calcium and vitamin A. Calcium deficiencies can manifest as neurological symptoms (shaking, lack of co-ordination) and animals exhibiting these symptoms should be brought to a herp vet. Vitamin A deficiencies result in feeding difficulties - the so-called "short-tongue syndrome" which is actually squamous metaplasia of the mucus glands of the tongue. There are doubts that toads can convert beta-carotene into retinol, so vitamin supplements with preformed vitamin A (retinol acetate, for example) are probably preferred.