Two of my favorite salad dressings:
Balsamic vinegar and olive oil - simple as can be, sprinkle some olive oil and balsamic vinegar (equal parts) on your salad.
Yogurt dressing - a cup of plain yogurt, 1/4 cup olive oil, 1/4 cup lemon juice, 2 or 3 cloves of garlic mashed, salt and pepper. Mix it all up, add more oil or juice if needed.
As far as black bean burritos, just use the mashed black beans like you would refried pintos. I go for simple burritos: beans, cheese, salsa. Maybe some onion or tomato if I feel like it, definitely avocado if I can get it.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson