I would consider going to someone who has experience in anal play with a male to teach her what to do, and more importantly, what NOT to do. If you've never had anal play before, might want to crawl before you walk. I would start with a silver bullet or prostate toy, before I just opted for an 8 inch dildo. Small steps, my friend.

You need to see a provider who is experienced with anal play, ask if you can bring your wife along so she can show your wife how things work.  Not knowing what she is doing could result in a total disaster for both of you.  Like London said, crawl before you walk.

Swim

anal entry

well..you could always hire a tranny..you will learn the ins and outs of anal sex very quickly..you probably wont need a strap on..they have one already built in..