Just got off my period today 2-25-12 wanted to know exactly when to have intercoarse im trying to concieve please help me?

It depends on start. The last day of your period does not matter. You should date your cycle from the first day of your period, and the best time to attempt conception should be midway through your cycle. For the typical woman, that is 14 days after the first day of your period. In any event, you should be taking prenatal vitamins, and can also take 600mg of Mucinex (guaifenesin) to help thin your mucus.
It depends. In general ovulation occurs 14 days (+/-) 2 days before you start your next cycle. So the best thing to do is track your cycles looking at the first day of each cycle and count backwards from there. Your cycle should be fairly regular in timing meaning that it is predictable within a day or two. If not, you should be evaluated by a gyn.