> I'm planning on a trip out West in the not too distant future and wanted to know if others have used them and what are they like.
I think I've only used a Flying J once but stay at Walmarts here and there. Basically, it's a parking lot. Some have separate RV parking areas.
> Is there electricity I can connect to?
Usually not. Very rarely you'll find truck spots with a pay-per-use electrical box. I can count on one hand the number of these that I've seen, though.
> How long am I permitted to stay(2hrs, 6hrs, ??).
We stay 8-10 hours. Usually arriving after midnight and out by 10am the next day.
> Am I required to purchase anything?(probably will get fuel anyway).
No requirement, BUT it's common courtesy to do so. Fuel is good if you're at a truck stop.
> Trying to find a stop or two along the way that I don't have to pay for to save a little money.
Be prepared for people to call you a cheap-ass for this mindset. Not me, though.