I know that Link exchange is the best practice in SEO. But, how can I invite or what I have to do for link exchange? Is there any format to invite others?

For link exchange you need to draft a mail with your details and offers to the webmasters of websites you are thinking to do link exchange with.

We all know link exchange is not an easy task and we have to search many sites and its more difficult to search for link exchanging websites but I am telling you simple techniques for searching link exchaning websites go to google and type link exchange against this type those keywords with whom you are interested in link exchanging.

Example :- Link Exchange: web

SEO Training Courses Classes.
Admec Multimedia.

I think you can always generate a good quality and informative content which can attract users and also moderators...

I Remember, The same question you have asked in some other forums also! Isn't it?

Okay, Fine. So, I can understand your problem now. Basically what you need is to offer some unique and attractive content to your target customers, as well as start some guest blogging, Forum posting and all likewise.