If you are going to venture out into the burbs, in particular Manayunk Brewing (which i totally would do during the summer on a nice day - huge deck and good beers), I would do the following:
Cross over the park from Manayunk into Mt. Airy and go to Earth Bread and Brewery. Good beers, awesome flatbreads. Have a flat bread and a beer or two, then get in the car and go down Germantown rd (same road as EBB) about a mile into Chestnut Hill and stop at that Iron Hill location. Paul is making some fantastic beers there, and has twice as many "seasonals" as he has house beers. From there I'd travel another 10 min down the road up into Ambler and check out Forrest and Main. These guys are making some really good saisons, and why wouldn't they? One of the guys (I forget who to be exact) used to work at McKenzie's mentioned in a previous post. From here you could head up to Lansdale and check out Round Guys Brewing, or turn around and start for home (as that is a pretty full day). Since you'll have your own car, and it'll be a little late (Forrest and Main doesn't open until 4pm I believe, and it is TINY in there), you could jump on Rt 309 which will be right in Ambler, take it down to the PA Turnpike, head west an exit to 476, take that south and do one of two things: get on the Schuylkill (rt 76) and go back into the city, or if you still have some time, go down one more exit on 476 and check out Tired Hands. I have not been there myself yet, but I have heard some amazing things out of this place.
In any event, I would hit those places, as all that I mentioned do not sell beer outside of the brewery (accept for a very limited supply of Manayunk beer). Yards, Slyfox, Victory, you'll find these guys on tap all over town (especially Slyfox O'rielly stout which is edging out Guiness in alot of places). It's too bad the NHC doesn't coincide with the Slyfox Goat Races. Hands down the best brewery event of the year in the area. Look it up for more info, Peggy is a two time champion!