I've said it before, not sure if you read it.

Did you have your saddle replaced? Male saddles will HURT..seriously, ESPECIALLY the girly parts. Get it replaced right away.

With a new saddle (and do not try to mess around with it, it has to be pretty much level for a reason), it will feel a little soreness for a little while. It took me about 5 to 7 days of riding for it to feel comfortable and not sore at all. It does get better over time. I made my big mistake at first by just accepting the male saddle, I was sore for days because of that.

Now I have a silly question - I know people have said not to use the smallest front gear with the largest back gear...I've done it, and I haven't had problems...unless if I'm missing something. I have double crank set, I'm not sure if that makes the difference.

If you want a nice flat trail, you definitely should try MapMyRide.com and do a search for your area - "Beginners", or put a search for a number of miles you want to do, etc. Once you get the map - click on "Elevation", it will tell you how big of a climb things are. Usually flats are between -1 to +1%, occasionally 2%.

I started out at 3 miles, and i was pooped out!! After a couple weeks of solid riding, I can go to 17 miles with climbs. I'm still learning all the time! Best of luck!