Ah, getting used to the saddle time. The best for me is to be on the bike consistently. IOW, better to ride 30 minutes a day than 2.5 hours only on Sunday. Which is what you're doing. Of course you also need the long ride, but work up to it. You may want to change saddles at some point. Most bikes come with a cheapy saddle because they know that no matter what they put on, many people won't like it. So start by slowly working up to a 150 mile week. Then try to ride a couple of centuries.

Machka has good starter info at: http://www.machka.net/century.htm
She's probably sick of posting it, so I'll help her out.

Here's a 10-week schedule for working up to it, but you should add some extra distance for your event:
http://www.planetpedal.com/goals/cen..._schedule.html
Also, 10 weeks is really optimistic. You're starting about the right time.