I know this forum is supposed to by "guys only" but I can't stand by and see bad advice being given.
Many people gave you good advice on your other topic.
Summary:
Lube. lots of lube. Buy some!
Patience. If its her first time and your first time, you will have to take it slow.
Respect. Don't shove it in there, and if she says it hurts, stop!
Practice. You might not get it the first time; don't give up!
My personal bit of advice is in regards to fingering. Fingering can help you find the entrance to the vagina, and you can then test it by stretching with more fingers.