Words could never express how much I love mushrooms. They are perfection, nature at its very best (that is, once they are cooked. I am not at all fond of most raw vegetables, but saute anything –or roast it in olive oil–and it is absolutely delicious).
Mushrooms go especially well with sausage, cream-based sauces and stews. We tend to make them as a side with boeuf bourguignon or with my personal favorite dish, gnocchi in cream-red wine-shallot sauce with Andoui sausage (goodness, just writing that makes me hungry).
Anyway, the mushrooms themselves are the height of simplicity. You just follow the steps that you take with any vegetable: heat some oil in a pan over low heat (or, if you want a super-rich flavor, use butter). Wash and chop up the mushrooms, then place them in the oil, making sure that they are spread fairly evenly. After a few minutes, add salt and pepper and stir some. Again, allow them too cook, stirring every couple minutes. They will cook fairly quickly; when you think they are done, taste to see if more salt/pepper is necessary. Enjoy!