In the process of changing my diet...?

ok, so i'm trying to be healthier and to lose some more weight. i walk/jog 5 miles on the treadmill 6 times a week and do some light weight lifting as well. right now i'm about 5'9 and 155. i'm really wanting to lose like 20ish pounds and to mainly tone up. so i'm doing a week long juice fast to help jump start weight loss and help with some cravings. then i'll slowly start adding in fruit, vegetables, nuts, whole grains, protein, and some low-fat dairy. so my question is, how long do you think it will take me to lose the weight and tone up? i'm on day 3 of my juice fast and my sugar cravings are pretty much non-existent, but i'm still craving some bad carbs. should i fast longer than 1 week? after my fast should i only eat fruits and veggies for a while and then gradually add more food in? also, what are some good, healthy snacks to eat after my fast? i really like quaker rice cakes...are those healthy? also, i'm vegetarian, so what are some good protein sources besides beans and meat substitutes? thanks