The inbound links is good (I believe), but if I put too many inbound links on my site, would that will damage the ranking or make it better?
How can you tell if you have enough inbound links or not ?
Let's say what will happen if I write many many ariticles and every articles have it's own page, then on those specific pages I put links back to the main site. Is it gonna do me any good?
You can't have too many inbound links, if you could websites link Microsoft's would suffer. Search Engines, especially Google, look for links to develop in a natural way. If one day 10,000 identical links to your site appear, then it will know these links are not genuine, that they are part of a link exchange program intended to boost PR. If the number of inbound links increase by 1% or less a day, and they are not all identical, but many share common keywords, then Google will see these links are naturally created and of much more importance.
It simply depends on the type of links. Exchanged links are worthless in terms of seo benefit. Try to get one way links from sites related to your theme. Try to avoid sitewides. The natural the better.
The no. of links enough or not depends on your rankings. But, one should always be looking to increase traffic through more links.
It will help if you make sure that the articles are original and makes sense for your visitors.
Yeah like everyone else said AND if you're going to go into article marketing, I would definitely submit articles to as many different article directories as possible. Google will devalue a bunch of inbound links all coming from the same site. But start with ezinearticles because they have high PR (they also have the some of the most stringent standards but it's worth it).