I have Peter Jenkins basic climbing DVD. It's very good. I'm use to DdRT, but would like to do some SRT. Are there any good DVDs on SRT out there? I'm especially interested in how do you tie the harness to the rope for safety when ascending.
What about a good rappelling device grigri e.g.?
I know there are a lot devices out there, but I;m looking for something you can lock off, safe, and not expensive.
If possible would fit the Poison Ivy rope I have.

I suggest a search of the old articles on this web site. Many a times we had long discussion on these topics including posting pictures and associated info.
Also, the tree climbers coalition site has a lot of info on SRT gear, techniques, types of ropes to use and other info that could help you get the basics clear in your mind before attempting to do it your self. Read the articles posted there first.

Learning SRT is not that complicated BUT it has special techniques that are VERY critical specially the switch overs from ascending to descending midway up the tree. Hope this can be of help and try to climb with an expert climber in your area that could point and suggest safety procedures in case you want to give SRT a trial. Welcome to the TCI site.

Thanks. I have visited Tree Climbing Coalition many times. I guess there's some things that I have missed.
Thanks again.

The Grigri is rated for ropes 10-11mm. Poison Ivy is somewhere around 11.5-.6mm. The Petzl ID (D20 S) is a good choice for a hands off/stop descender for PI.
-moss

The Grigri would have been a good choice but as you said it's only good for up to 11 mm.
I saw the I'd. It's quite expensive. The Stop and Simple (up to 12 mm ropes) are 2 other descenders.
Any one famaliar with these?
Since we are on the subject, what about ropes. I've seen a number of comments on different ropes, velocity, fly being two.
Any opinion on a good rope (11 mm or below) that will takes knots as well as mechanical devices.

The Fly is a popular rope that works with either system DRT and SRT. I do not have one but some comments I have read sounded positive. ( It has problems with "milking" when it is new.) Nick Araya is the best adviser on ropes and splices, send him a request for advise by e-mail.

Practice your DRT and all its variations in methods and techniques until you are very confident and later graduate to SRT if you have Very Tall trees in your area otherwise it may not be worth the extra investment in gear and stuff. I have SRT gear but mostly use it when I go to the yearly Rendezvous. I will probably take it to Colorado this year.