Protein -- how much is enough?

Maybe I am opening a can of worms here, but I am very confused about how much protein I truly need to be eating. While I am not weightlifting, I am doing enough yoga to make my muscles very sore sometimes, and I want to have enough protein to hopefully prevent muscle loss as I lose weight. Is there a good formula for estimating this that takes into account that I am NOT a bodybuilder and am very out of shape now?

eat your weight in protein,

a good rule of thumb is .85g of protien per pound of bodyweight, even better if you can calculate "lean mass" and to it to that.
Tinned Tuna is an exellent source, as are whey protien shakes. If you are doing Yoga in teh evening you may want to take a Cassien protien shake as this is more a long release and with supply your muscles with nutrients while you sleep to help prevent soreness.
You are right to prevent muscle loss during fat loss otherwise its only scale weight which could include lean tissue also.

There are also non animal derived protien powders should you wish.