If you google map portland and zoom in you will see back cove, there is a trail that runs around the cove next to baxter blvd, very nice paved path that is bike/run friendly. Always a good start, if you come off the cove and run the eastern promanade and then come down commercial into the old port that is always scenic and worth the trip minus the occassional slow down for a crossing car.  If you cross into South portland, run shore road out to Portland head light, if you run route 77 it is part of the B2B race. Hope this helps.

try meeting up with Gomez's and Jeff's group..sometimes they get 5-10 guys together and run 7-7:30pace.

Sorry, I was in Memphis last week, didn't see this.  There are a lot of trail options in and out of portland if you know where to look.  Back Cove, Mackworth, bird sanctuary, evergreen, etc (which are all within running distance of downtown if you are doing 20+) - if you wanted to drive you could get even more options, presumpscot, jungle run, twin brooks, pineland farms, bradbury, eastern trail, pine point, etc.