I use cages to support the vines, although half the time the plants refuse to stay inside their cages.
Little devils.
The fruit need plenty of calcium. You can supplement a regular fertilizer -- I use Tomatoes Alive from the mail order site Gardens Alive -- with eggshells. Dig a small hole about 6 inches away from the plant (you don't want to disturb the roots if you can help it), and plop in some crushed eggshells. Work the shells into the soil. My plants get a weekly eggshell boost after Sunday brunch.
Two essential times to fertilize: when you plant, and when the plants start to set fruit.
Avoid fungus problems -- black spots, wilting, yellow or brown leaves -- by watering as low to the ground as possible, and watering in the early morning. Most fungi are soilborne, and if you can avoid soil splashing onto the leaves, so much the better.
Good luck!