Charles County would be best. We want an indoor wedding due to how crazy Novembers weather can be. Religion really isn't a factor. We would prefer a church where we wouldn't have to get confirmed as a member.
Do you want to get married in a church just for the look? I mean, you could be ruling out some pretty nice venues if that's the case.
Have you looked at Middleton Hall in Waldorf? They have a room for the ceremony and a separate, larger, room for the reception. I've been to a couple weddings there, they were both really nice.
Middleton Hall
There's also Swan Point, which is amazing! We looked here for our wedding but it was too far for some of our guests, though it was absolutely gorgeous, so we decided to go with Colony South (and we were VERY happy).
Maryland Golf - Swan Point Yacht & Country Club - Swan Point, Maryland - DC Golf
Which brings me to my next suggestion, hehe...Colony South. It's not in Charles County but it's close, in Clinton. We chose to have our ceremony outside in the courtyard but they do have an indoor room for it as well as a larger room for the reception. I loved it there
Colony South Hotel & Conference Center
There's also the Jaycee Hall in Waldorf. 2 of my friends got married there a few years back, it was so nice! Again, they have a few rooms to choose from so you can have both the ceremony and reception there if you wanted (though my friends both only had their receptions there).
JC Center Main Page