"1) what do I need to add to my topsoil for my veggies? I am growing corn, pumpkins, beans, cucumbers, and peas. "

Probably the most important thing is to add as much organic matter as you can. If you're going to use synthetic fertilizers, you can use something with 0 for the second and third numbers (like 21-0-0).

"2) I have started 1/2 my plants indoors and will harden them off to be planted after june 9. The other 1/2 of my seeds I'll put in the ground on Memorial day. From experiance is it better to start indoors or put seeds right in the ground in this climate? "

Is Heber at a higher elevation? How far north is it? I usually use Mothers day as my rule of thumb for planting the garden. I live along the Wasatch front, about halfway between SLC and Ogden).

"3) I would also like to start to compost. How do I start? "

The easiest way is to just start piling things up, mixing high N matter with high C matter.

Some examples of high N are coffee grounds (you can get them for free from Starbucks whether you drink their coffee or not; just go in and ask if they have grounds for the garden), manure, grass clippings (although I prefer to mulch mow and return them to the lawn), most vegetable waste from the kitchen, etc.

High carbon things include leaves from the fall, chipped wood (although it there is a lot of young wood, especially young wood with green leaves, it may be higher in N), sawdust, shredded paper, pine shavings, etc.

If it stinks, it probably needs more C and or needs to be turned (or it could be too wet, but that's less likely around here). If it doesn't get hot, it probably needs more water, more nitrogen, or needs to be turned.