Couple questions about SEO

I have a webhost that allows me to host unlimited amount of domains and I have two sites that I want hosted with them. They will share the same IP address, but one will link to the other. Will this hurt my site's ranking or does this not matter?

And when providing SEO services, how do they go about it? Do they take your main page's HTML and optimize it for search engines or do they just tell you what to do and you manually go in and do it?

Others will correct me if I'm wrong, but I'm pretty sure you can have as many subdomains on the same domain as you wish and that Google will treat each seperate subdomain in terms of content and keywords individually. Go for it. However, do not try to interlink between your own subdomains to get high SEO rankings; it's an old scam tried before and now Google considers this in its algorythms.

And the first place to start on your site is with the main index page - optimize that. When you're happy with it, submit it to the main engines. Logically, if it's well optimized then the Google and Yahoo bots will find and trawl all the other pages on your site. Don't need to submit each and every page.

Hope that helps.
Richard.

Thanks for the help, but I think you misunderstood me.

Say I have site www.x.com as well as www.y.com and both are hosted under the same web host (identical IPs too). Is it okay if I have x.com linking to y.com and vice versa or is this frowned upon by Google?

And when I want to have my site optimized by a professional, what goes on? Do I submit my index home page's source code to the optimizer, or does he/she just review my page and tell me what to do and I manually go in and optimize it myself?

I think there is some sort of penalty if you do too much interlinking between sites on the same IP, but no one really knows the what is safe and what isn't. I generally try to keep it to a minimum.

Some SEO companies will change the code for you, some will just notify you of what needs to be changed, depends on the company.