It's pretty easy, especially if you go on the towpath instead of going out Umbria, which is a longish hill (rewarded by a pretty neat short downhill which can be hair-raising if you're not careful, so take it easy on that).

If you're just starting out, and assuming that you're not riding on really skinny tires (less than 25c) I'd take the towpath- it's packed gravel and boardwalk, and the scenery is very interesting- a mix of the old industrial Manayunk, woodlands, and riverside. You're bound to see some interesting birds (there are great blue herons that hang out where the canal has filled in, just before the Black Rock dam. You'll see the signs for you to turn left off Main St., just in front of Human Zoom bikes, which will be on your right. When you get to the end of the towpath, you'll be making a right up a pretty steep (and very short) hill, all on well-worn cobblestones with sizable gaps between them, so probably best to dismount and walk up the hill- it's only about 100 feet long.

From there, you cross the RR tracks, make a left on Nixon (which is where you'd come down onto from Umbria if you had taken that route, so on a busy day watch for fast cyclists coming down that hill). Take Nixon out to the "Y" (about 1/3mi or so), and bear to the right to go up another short (and paved) hill, bear left at the top and you're on the SRT. From there, it's a pretty straight shot to Betzwood, which is across the Schuylkill from VF. Assuming that you want to go into the park (itself a nice ride, with smooth rollers and very pretty scenery), cross the Betzwood bridge (best to do this on foot- it's narrow and can be disarming to those who aren't familiar with it)- hanging a left after you get off the bridge will take you to Trooper Rd. which you'll cross to get into the park. If you do decide to go into the park, it's easy to get disoriented, so best to have a map handy, or stop at the gift shop at the chapel- they have maps there.

Have fun- it's an easy ride, that many of us use for distance training (e.g., going out to Collegeville makes it a nice 60mi R/T). On a weekend ride, just be sure to stay right and call out when you need to pass- you'll find a few groups out there and they can get going pretty good.