Hi Mel82,
I wouldn't stress about it too much. But I have heard putting a pillow under your hips can help the fellas in the right direction! Just don't get up for about 20/30 mins...
as for positions him on top for sure - and as deep as possible (sorry TMI) so sperm are right by the entrance to your cervix..
Every other day seems to be the popular choice - or maybe everyday around ovulation.
Hope this helps but I think there are much more wise girls on here that can give more advice..
xx