My dad is looking to get into riding his bike again. He used to have a super heavy Specialized mountain bike, but it's been on the side of the house for a long time now. He wants to use it to bike around town and take it on the occasional recreational bike ride. I was going to get him a road bike, but he mentioned wanting the ability to go off-road when he pleases (however, the majority of his riding would be on pavement).
I was looking at the Bianchi Volpe or the Kona Jake. Any others I should consider in this price range (nothing over $900)?
A lot depends on your Dad's idea of off road. If we're talking about fire roads, bike paths, smooth single track either bike should be fine. The Bianchi Volpe is steel and has a triple crank designed for touring, i.e. lower gears. The Jake has an aluminum frame and a triple crank, although the gearing is little higher (more road type) than the Volpe.
I would go with the Volpe, but that's me. There maybe other choices out there. I'm sure others will chime in.
I got myself a Cannondale X6 for C$1100 (about US$900 on current exchange) and would seriously rate it as a bike to do what your Dad wants. I've raced it all of the cross season up here, plus commuted on it, plus taken it riding on various mountain bike trails (obviously not over major drops or anything serious) and it's performed well. I have changed out a couple of bits to suit personal taste, but otherwise it's standard. For the money he's getting a relatively light bike (about 20lb according to C'dale) with bomb proof enough kit that still performs OK - jeez, it is almost enough to convert a lifelong Campag fan to running a Shimano equiped bike!!
Getting to this I tried Felt (over the price you want to pay), Norco (it kept feeling like it was about to slip out from under me - on the road!), Kona (nice kit, but it felt really dead and heavy compared to the Cannondale - although the wheels are nicer) and a couple of more exotic/pricey bikes. I'll confess to being a Cannondale fan before I started, but even with that, to my mind the 'dale is the clear winner in this price point ...
Regardless, at the end of the day, the big thing is that your Dad tries the bikes and finds something that he feels comfortable on - manufacturer's spec or the fact that world champs have been won on something or whatever other marketing and manufacturing B-S get put out there all come a distant second to how any bike feels to the person who's actually riding it ...
2013 Kona Jake, 2008 Kona Major Jake, 2013 Kona Jake the Snake, 2006 Kona Kula, 2012 Ridley Excalibur, 2008 Surly Long Haul Trucker, 2001 LeMond Buenos Aires
Does your dad want drop handlebars? If so, either the Volpe or the Jake are good choices. I've got a Jake and I use it very much the way you've described -- 50-100 miles per week commuting on good road, weekend rides up to 100 miles, cyclocross racing, and the occasional ride on an off-road trail.
On the other hand, not everyone loves drop bars, so if he's going to be doing mostly short rides and he's really serious about doing some trail riding, some sort of flat bar bike might make more sense. I've got a Marin Muirwoods 29er that I use for commuting in the rainy season, and it's pretty fun to ride. This summer I plan to put on some knobby tires and a lower geared crankset that I expect will make it a better trail bike than my Jake.