roof vent installation?

What type of roof vent installation are you referring to? There are several types, from fan, to forced air. If you are unsure of what type you want, you should check with a home center such as Lowes, or Home Depot to get some advice. Before you decide to have one installed, check with others to get recommended contractors, as they need to be bonded and insured, or else you could be held liable for any injuries or damages they might cause. You also save money later if you have it done correctly the first time.
ridge vents? solar vents? turtle vents? power vents? a little more specific please.
I would stay far away from the Home Depot for advice on roofing. It has been 11 months since my roofing project started and they still are not complete. They have now installed three roofs and did over $1,000.00 in damages to my house. Once they have your money they do not care about customer service. You can see my web site at http://www.freewebs.com/myroof read my journal of how phone calls and emails are not answered for weeks. After installing the first two roofs they did not repair the old roof vent holes properly. Even when the Home Depot project manager was on site when the 2nd roof was removed they did not repair the holes correctly. Thank you Don Wenzel Oxford, Michigan