Question for good guitar players?

If you're playing the key of G then G would be (one of) your root note(s). So to answer your question, yes you could definitely be using the G pentatonic scale but there are also a lot of other scales that could be used as long as they are played in the key of G. There are exceptions to ever rule though. But for beginners, try not getting too fancy by mixing things up too much and stick to the root notes. Once you have that down you can start learning all of the weird things you can do with notes and scales. Golden rule: if it sounds good, it is good.

http://ca.answers.yahoo.com/question/index;_ylt=Au...

This is an answer to your question I gave another person a few weeks ago. To save time and finger fatigue

I now just link to it. It got good reviews from some of the other top contributors.

You've got the basic idea right.

But try for more than just pentatonic scales. You rob yourself of two notes that you could be playing in a scale.

Pentatonics are the beginning scale not the ending, penultimate scale that so many noobs on here seem to think it is.

Try E minor pentatonic on the 7th fret for jamming in key of G. You can get lots of mileage from that.

Russell E's answer is perfect. I suggest you take a look at it.