Here are some suggestions:
1) Got to to the library and get last year's articles from Consumer's Reports on vinyl siding.
2) Do a lot of research - this is a big expenditure and the research is well worth it.
3) Get many, many estimates from companies which have been in business for at least 5 years, preferably 10 years or more. Remember that a ten year warranty from a 10 month-old company is generally worthless. I got new siding, gutters, downspouts, roof and facia covering from a company in business for 50+ years. I had some minor problems on the gutters and some major problems with part of the roof, which were fixed very promptly. A company without a 50 year track record may not have been as responsive.
Also, where do you live and what is the climate? Is insulation a significant concern for you for heating or for cooling? If so, then you need to do some research on Tyvek wrap, foam board under the siding, plus products such as Craneboard, which is a vinyl siding with a foam backing.
Consumer Reports discusses the fact that your first criteria is the selection of a brand and line of siding and that the installer is a secondary consideration. I agree completely. The proper selection of your product(s) is your first concern.
I picked Craneboard with a Tyvek wrap. I would have added some thin foam underneath the Craneboard, but this would have made my exterior wrap too thick - my window trim would have been flush with the siding, which is an appearance which I don't like. Others may not consider this a problem.
Also, remember that there is a lot of markup on exterior renovation. Don't be afraid to negotiate in the same manner that you would on a car purchase or an appliance purchase. You should be able to get 20% off of an initial estimate if you are a good negotiator A siding salesman doesn't like to cut his margin this thin, but he will if necessary.
Remember - you are spending a lot of money and a bit of research is time well spent.
Good luck,
Gideon
============
*-------------------------------* NEVER FORGET!!!
formatting link