Hi Imran,
Research is key to success BUT only when performed in the correct way. For instance, it's not worth doing heavy keyword research to then spend a week or two getting the site up and running, then another week submitting to directories and then a good few weeks/months trying before you're even listing on Google, Yahoo etc
Regarding keywords I'd start off by simply making a listing of 10 ways you personally would search for your product. Then I'd use Yahoo and Google to search for them and find out what your competition will be roughly like and throw out any which will will be unattainable for you. I'd then put any more keyword research on hold until you're ready to "go live" with your website.
Once your site is ready on your machine, THOROUGHLY TEST IT! I can't emphasise this enough... People don't buy from sites with broken links, technology that doesn't work, SQL errors etc!
Site finished? Next stop is your hosting and domain name. For hosting I'd start small and upgrade when needed but make sure your chosen hosting supports any technology you're using (like PHP, MySQL, ASP etc) and that they are trustworthy and have a low down-time.
Once your domain name is pointing at your hosting (i.e. people can see your site using your domain name) you're ready for the tweaking like meta tweaks, keywords, content tweaks.
Regarding your domain names or number of sites it really depends on what you're reviewing. A review site generally reviews various things all in a similar vein, thus if you have a site called
www.myreviewofhollymannsguide.com and you ONLY review the one guide it's not really what I'd class as a review site; it's more like piggy-backing straight onto sales of the item.
If, however you were to review various guides all on one site and have all your affiliate links on it with honest ratings it works.
If you're looking at getting sites you have various options. You can create your own site using a free template from the web.
You can use Wordpress or a similar pre-made one (http://www.hollymannwebsites.com/) you can get the site and setup for free but you have to pay for hosting etc up-front.
You can use a CMS (Content Management System) to create a site which makes everything as easy as pie... Once it's set up that is! The set-up of CMS isn't an easy thing for non-techies.

I'm just starting out with ebooks so I can't help you on that front I'm afraid

Post edited by: ScattereD, at: 2007/02/20 11:46