i was just wondering what the shortest bulking period is-whilst still making reasnable gains , i understand the shorter your bulk, the less muscle you will gain..but is there any reason why i couldnt say bulk for 10 week periods, then cut back until i am happy, then bulk for 10 weeks again ect, or do you have to bulk for longer periods?

10 weeks is really not that short of a time. I think that would work fine.
Something similar that I've seen gaining popularity lately is throwing a few weeks of cutting into the bulking period in order to keep fat gains at bay. Something like 4 weeks of bulking followed by 2 weeks of cutting and then repeat. (I'm actually doing this right now)
The bulk John just ended was set up in a similar fashion.
Check out this video (http://www.bodybuilding.com/fun/insidethelife5.htm). It's where I originally got the idea.

thanks George:) i was a little concerned because i do remember someone saying in the "things you wish you knew when you first started" too not chop and change beetween bulking and cutting to often or you`ll just spin your wheels. mabey they was talking a matter of days. if i can bulk for short periods followed by cutting back too a few pounds above start weight then this would make me feel a whole lot better and is the only way i can feel totaly safe about not getting fat again :lol:

might go for 8 week bulk periods and then cutting until i am 4/5 lb heavyer than the start weight:bb:

cheers mate