So, it's never too late to learn and try out some new things.
Go here and take a look:
Give Her An Orgasm - GiveHerAnOrgasm.com
Or get this to read:
Amazon.com: She Comes First: The Thinking Man's Guide to Pleasuring a Woman (9780060538262): Ian Kerner: Books
Just don't let her feel any pressure from you about this, or she may start to feel frustrated and disappointed. Always be upbeat and positive.
Best wishes.