www.ebay.com is a really good website but if you can not find any on that website then you should try www.Craigslist.com easy and simple.
Generators normally dont have any software. You may be able to find instructions online.
There are quite a few sites where you can find generac generators online. Some are: http://www.electricgeneratorsdirect.com/power/generac-generators.html and http://www.apelectric.com/
briggs and stratton generators usually run from 159 to 179 but if you find them used at a pawn shop or on craigslist them you might end up spending a lot less then that.
There are many places online where one can find and purchase Yamaha generators online. Some sites to check would be Yamaha Generators (dot com), Sears, and Electric Generators Direct (dot com).
Solar power generators a good options for power backups during hurricane situation. At Mysolarbackup. com you can find a lot about solar generators. Even you can order some.
This site, http://www.electricgeneratorsdirect.com/stories/351-Serious-Electric-Generators-Worth-Bragging-About.html, contains some great electric power generators.
You can find a good selection of gas generators from Home Depot. They have many different generators to choose from at several different price points, so you should find exactly what you are looking for.
Propane generators are great to research. You can use wikipedia to find information that describes the difference between propane generators that would be useful to you.
Some sites that sell diesel generators include GeneratorJoe, Marind, Tracktorsupply, and Diesel-generator. They can also be purchased online from Amazon.
Some websites that offer generator reviews are Consumer Reports and Planet Generators. These sites offer reviews for a wide variety of generators of different brands and models.
Some information about standby generators can be found here. http://www.generatorjoe.net/html/stepxstepgenerator.html According to this article, standby generators are for emergency use only. You should use a prime generator instead if you are lighting up your patio lights daily.
"Some primary gas generators in the humans would be food that are particularly high in fiber or other compounds that our intestines find difficult to digest. Most beans, if not eaten on a regular basis, are a great example."