Re: link other sites question
You will probably find as your site matures other sites will start linking to you without you even knowing about it, this is how the internet works. As answered above, no one is going to mind you linking to them as you are creating another door into that site's service.
I make many sites for wedding dress companies and nearly every week someone steals an image from one of my sites and posts it on a forum or another site with a comment like 'This is a dress I want to get married in if someone ever asks me!' .... Most of the time they add the photo with a link to the site (sometimes intentional, sometimes not). This saves me loads of time having to market these sites when other people unintentionally and innocently do it for me!
Don't aim for success if you want it; just do what you love and believe in, and it will come naturally.