Mike, It's great that you are asking these questions and doing your research. I've seen and heard of all sorts of things happening to clients who blindly followed guides into the mountains. Get a copy of Accidents In North American Mountaineering
for 2006, 2005, 2004 as far back as you care to go. They are available for $9 each on Amazon and carefully explain exactly what has gone wrong and how it could have been avoided. You'll be able to see these situations before they arise.
As for guides on Mt. Washington they are very informative, helpful, and not at all after your cash. However they do have to cater to the group dynamic of the trip, and you may be frustrated by how weak and mentally uprepared your fellow clients are. The guide must look after them and it can stifle your personal experience.
I've run into many guided parties on all routes on the Presidential Range and they always frustrate me with their incompetence. It seems to me most clients simply go into the mountains without learning anything about them and cause major problems for everyone else.
Ever since I began I chose to go without a guide and it has been very rewarding. If you can find someone with some knowledge to go with it would be much better in a smaller two or three person team. Save your guide money for more technical instruction like crevasse rescue, beginner ice climbing, and such.
I'm solo in the area quite often and would be willing to go with you if you like. Drop me line if there is anything else you'd like to know about the area.