Pasta salad is pasta cooked until soft with vegetables and an Italian dressing. I assume I need to boil the vegetables separately, but am blanking on how long is appropriate. Thoughts?
My answer would be "not at all". My pasta salad involves only raw vegetables - carrots, peppers, celery, and similar things you would put in a leaf salad. The contrast between the soft pasta and the crunchy veggies is part of the appeal. Just a data point.
It's all personal taste, really.
Raw is definately the easiest preparation, but there are some things that I find a quick blanch helps (eg, brocolli). If there are any vegetables that you find a little too crunchy, try a quick blanch (or steam), and see if it helps improve the texture.
If you're lazy like I am, just chuck the cut up-vegetables into the boiling pasta water when there's a minute or so left 'til it's done. (although, I admit, if you guess wrong on when a minute or two left is, you're out of luck, as it's not so easy to just extract the pasta or the vegetables, unless you're cooking something like tortelli that'll float.) You can also blanch 'em for a minute or two before adding the pasta.
As Kate and Satanicpuppy have said in the comments, as pasta salad is served cold, the usual preparation is to simply leave the vegetables raw. However, if you really want to cook them, I'd suggest slicing them relatively finely and sauteing them lightly, perhaps with a little balsamic vinegar.
I like to blanch my broccoli 1-1.5 minutes. I also like to sautee my onions,peppers, carrots, zucchini. However I do allow them to cool completely before adding to salad. Ham diced up and mini pepperoni thrown in with Italian dressing with parmesan cheese thrown on top with little celery salt and done. (My grandma also had no teeth) and that's why everything was cooked.