• A lot of people will tell you not to wash mushrooms, or just brush the dirt off them, because they'll absorb water or lose flavor.  I (and others) have not found it to make any difference, and since they're always so dirty, I say wash 'em!
• The gills of portobello mushrooms can be scraped out with a spoon.  They're fine to eat and don't taste bad, but if you're sauting them, they'll stain whatever else they're cooked with.
• The stems of some mushrooms are either inedible or tough and fibrous, so you may want to remove them.  Usually I'll break it off of the portobellos and shiitake but leave it on the crimini and white button.
• After a few minutes of cooking mushrooms, they'll release a lot of liquid.  Most recipes call for them to be cooked until they reabsorb most of it.

Mushrooms

Vegetarian recipes with mushrooms

• Asparagus Ragout with Polenta
• Charred Mushroom and Baby Spinach Salad
• Goat Cheese Stuffed Portobello Mushrooms
• Grilled Bistro Pizza
• Lemongrass Soup
• Mustardy Portobello Mushroom Pasta
• Portobello Bistro Burgers