I am going to Yellowstone Sept. 22 - throught Oct. 1

I am thinking I will fly in on Friday day/night - spend the next 7 nights in Yellowstone, then head to the Tetons and spend 2 nights there before flying out on Sunday the 1st.

Something like this:
Friday - fly in - stay at OFI
Saturday - Old Faithful Inn
Sunday - OFI
Monday - OFI
Tuesday - Lake Yellowstone
WEd - Lake Yellowstone
Thursday - Lake Yellowstone
Friday - Drive down early to Tetons - Signal Mountain Lodge
Saturday - Tetons - SML
Sunday - Fly home and be SAD!!!

That woud give me 6 full days in Yellowstone and 1.5 full days in Tetons.

As far as Yellowstone lodging, Old Failthful area is open, Mammoth hot Springs Hotel and Cabins as well as the Lake Yellowstone hotel and Cabins. (nothing else is open).

I just made reservations at Old Faithful in for 3 nights and Lake Yellowsonte for 4 (thinking I would se the West side and South side from Old Faithful, and the East and North East from Lake Yellowstone.

Question - do you you think I should stay at Mammoth Hot Springs for 2 or 3 nights and split it up between the 3 areas. )for example fly into Bozeman and stay at Mammoth) To change hotels three times is more hassle, but if it makes that much of a difference I would want to.

Also, while I am at it does spending 7 nights in yellowstone with 6 full days make sense in yellowstone or should I leave and head to the Tetons and stay one more night there giving 2 full days in the Tetons.

(this is my first trip).

Any suggestions for the itinerary on how to make the best of time would be great!!

Your itinerary is fine. As yours was an opinion question, I will offer mine. Stay at Signal Mountain Lodge two nights, enjoy some hikes in the Tetons, have a Snake River Lager when you get in from your hike and order the "super" nachos. Great way to end a trip to one of the USA's great areas. Have a blast.

This sounds like a great trip but since you're asking -- I would replace either OF or Lake Y with Mammouth. I would also spend 2 nights in the Grand Tetons. Have fun!

I have decided to add Mammoth to the trip.

Stay at Mammoth the first 2 or 3 nights, then OFI, then Lake Yellowstone, then to the Tetons.

Does anyone have suggestions on teh room type for Mammoth, Cabin or inside the hotel?

I prefer the cabins at Mammoth to the rooms. We have stayed in both and the rooms only have a claw foot tub, no shower. Cabins have a shower only. We stayed in the cabins last year and they had been renovated since we were there in 2001.

We had 3 cabins in the Mammoth for 2 nights last Aug. and enjoyed the fact that you had nice porch to sit out on. We could also see & hear the elk right outside our door in the a.m. Very nice area and enjoyed both days here. Ate both our dinners in the lodge and enjoyed our service & dinners there as well.