For quick reference, check out pdfs of these maps. To view them you'll need to do a quick sign-up on the Keep and Share site...only takes a minute:
The first link is a drawn-to-scale scale map showing all of the park's trails, although it doesn't list trail names. To be honest, the trail names are not all that important. You really can't get lost here if you stick to the trails since they all loop around.
We rode Mine Falls today for a little over an hour. We parked at the end of Whipple Street, started out going west on the yellow trail, passed under the turnpike (this part is really noisy) and then followed the green trail to the gatehouse and dam.
Retracing our steps, we returned to our starting point and then headed east on the blue trail that took us behind the Millyard (shown above) in downtown Nashua. Doug says the park seems to "shrink" each time he rides it. That's probably because he's getting more familiar with it!
The second link is a map (not drawn to scale), that has a description of each of the seven entrances. This map is helpful if you want a general overview and points of reference.
So there you have it. I wrote a longer post about Biking Mine Falls Park last year. If you're a newbie to the area, you might find some useful tidbits there. Happy biking!