Advice for the bedroom?

Ok so hears the deal, I am 26 years old and I used to be really shy which really hurt the love life in the past. Over the last couple of years I have worked really hard a breaking out of my shell, and am now having a great time going out on dates and meeting women. I have met someone who is very attractive and so far things have been going really great. The problem is as far a sex goes I am very amateur, I can count my experiences in that department on one hand and as far as they go, when alcohol was involved I could last quiet a while but when sober I think I was pretty disappointing. I am sure that this girl is way more experienced than myself. Does a man really develop more stamina over time? And what exactly makes a man good in bed? Any tips? I really don't want to disappoint when it is my time to shine.