I wouldn't grow in milk jugs just because you have so many other more efficient things to use; but if thats what you want to use, make sure that you cover it up completely so no light can get to your roots. When light hits roots for too long they turn green and that is not a good thing. It will cause your plant to grow VERY slow, if not at all.
There is a lot involved in knowing the right time to pick your bud. There is not just some set time as to when the buds should come off the plant. Do a ton of research on this site, and you will learn that everything you need to know is on this site. READ READ READ my friend