I have my floor ready to work on. I'm following instructions given by the pros from this site by running the boards at right angle to the floor joists....the question now is I was thinking of running a border around the perimeter of the room; obviously, there will be 2 sides that will be parallel to the joists...is this advisable...can I do it with just face nailing and glue or do I have to get down to the crawl space and reinforce the permiter?

Thanks!

Depends how wide your border is going to be. 2ft. or less, I wouldn't bother.

It is also going to depend how much subfloor you have on top of the joist, now.

The width of the board is 3 1/2 inches and the subfloor is 3/4 inches T/G ply. I intend to run only one board width around the perimeter of the room. Thanks

That 3/4" ply is great. Go ahead with your border. No need to brace up from below. Personally, I'd make it a little bigger. Using only one board seems odd to me.

If the one board is say a foot in from the walls, it isn't too bad. But right up against the walls, anything less then a foot wide, looks goddy.

Thanks for the advice Floorguy (and Gary too); I'll lay it out first to see if it looks good 'cause this room is 25ft x 15ft and it's on the 25 ft length that the "border" would run parallel to the joists. I'll try both your suggestions as I have enough short lengths to do the inside border thingy without having to do a cut.