While creating backlinks should I link to my whole blog or only the post related to the topic of the other blog I am commenting on?
Yes, just link to post related to the topic. You could also use a keyword linking to another post, and that will work fine. The rule is, hide your blog to the third tier links, while using keywords to promote it.
Internal linking is very helpful especially if you topic is relevant to your previous post. Rankings/PR will be distributed equally, but just remember not to over use it.
Static Linking - In this type of linking, linker links the actual code of the library direct into the code section of the executable. Example: Linking C and Graphics library in Turbo C++ for MS DOS. Linking an application with a archive contains .obj files. Dynamic Linking - Dynamic linking does not link the actual code of the external functions. Instead it prepares a list of imported functions in .idata section and a stub code which actually jumps to the external function by address.
It can be done easily by installing plugin. If you are using wordpress then my recommendation is to use: ELI's Related Posts
I think you should be concern about each and every blog post made on your blog. And build links for every blog posts to related blogs through blog commenting.