SmokinAce said:
Where should I start out on the Wiss?
There are quite a few options really... check out this thread at phillymtb.org:
http://www.phillymtb.org/index.php?option=com_jfusion&Itemid=4&jfile=index.php&topic=1369.0
From the Lansdale area, I'd park at Northwestern Ave and head to Forbidden Drive, then pick a trail that looks good. The first trailhead you'll come to, heading towards Valley Green Inn, would be the Monster right after Bell's Mill Rd. For an introduction to the park, that might not be the best unless you're into brutal climbs right off the bat and that section can be confusing until you know it. I might ride past Valley Green Inn and then take the second trailhead you come to (not the one right by the Inn). Head up the cinder path then make a left onto the first trail you come to, then ride on. That's just my opinion, of course.
Also, the PMBA linked to above has organized rides weekly, and you'd quickly get to know the park.
Oh, and a permit is necessary for what they consider the "upper trails", which pretty much just means anything besides Forbidden Drive.
http://www.fairmountpark.org/trailsintro.asp
I'm not advocating NOT getting a permit (especially if you start riding there regularly), but I will say I haven't seen anyone checking since the first ranger surge early this summer.
Good luck! It's a great place to ride.