It will probably take a few days for it to start. 2 or 3. Once it starts, it doesn't stop. Don't think you can be drinking any alcohol at all either. It will fuck you up bad. You might break out too as your body is cleansing itself. don't worry, thats normal. Just your body expelling toxins. You might also be more tired than usual which is also normal. When you are done, you will feel GREAT.
I've done it a few times...its some good shit. Those organic lemons can get expensive but it is your health, so you either pay now or pay later. Visit http://therawfoodsite.com/ for some tips. Once you get to day 4 its easy and you'll have a lot of energy. You need to do a minimum of 10 days although you will see major results by day 21. If this is your first time shoot for 10 or 14.