Common people - the internet is packed with nude photos of couples and women having sex, it might not be to your liking, but I don't think it's a crime...
First of all, you need to ask your wife is she's cool with that - personally, I like having nude photos of myself online, my husband's a photographer by profession and this is one of the ways we share our love. So far it's done nothing but good to our relationship.
Doing this without your wife's permission is not only nasty but illegal, I believe it can kill your marriage and get you sued if she find out. So, first thing is getting her permission. Let say your wife's a little more tolerant then the people who answered this thread then you have a lot of options:
www.alt.com
www.youporn.com
If you mark your photos as "restricted" on www.flickr.com, you can share them with a lot of people in different groups - that's my personal favorite, cause people can favorite your picture and comment about it.
Or - just start a personal blog with your wife and put up the pictures there.
For more option google "amateur porn submit" and ou'll find loads of other places.