I am recently adding my page to different sites,but when i check homepage of that page,it has a page rank,but when i search for the "link" page of that site,it has nothing. So does this mean it will not give back anything or the main page rank is counting for the sub-pages page rank?
Best practice is to get backlinks 'only' from relevant/related niche sites. It will give your 'pure' boost in ranking.
It will help but the value will be minimal, thats why you only manage PR3 or PR4 after you submit to few thousand directories.
as long as the "link" you mention is indexed, it will count as a link, but as mong said, related niche can boost ranking.
actually PR doesn't matter at all, whether it be the page, the domain, or anything else. Get relevant links, on sites with unique information, that is high quality, and on theme with your website. That is what is important, not some silly number.
I don't really understand what your trying to say because you used a comparison without comparing it to something. It would be much better than what? If PR is your main concern when looking for links, you need to analyze your SEO practices imo. Theme should be your primary concern, related to your website, then quality of the content, then you can worry about PR (personally I find it better to evaluate the quality of their links on yahoo, as it gives a more current outlook on the website than PR does). Other things are the number of OBL on the page or the title of the page. If your anchor text / keyword is in the title of the page your link is on, thats a huge boost in the relevancy.
It actually might happen that the links pages are not even indexed in Google. Then obviously the backlink is useless as it doesn't exist for Google. Even though the PR is 0 at least make sure that the links page is indexed.
every small link counts. no matter what PR they got as long as it's free. but if you pay for it make sure you got PR link that deserve the money you paid.
When it comes to backlinks, quality is much more important. You can have one quality link that can easily beat 1000 worthless links. Contents around the links are very important. For example, there are a lot of signature links at this site to sites that have nothing to do with web design or seo. These signature links are not as valuable as links from pages that have contents relevant to the sites they are pointing to.
get relevant back links. don't worry much about back links. better get relevent site from area or country it is better the higher PR not relevant back link.