can anyone tell me all the things involved with creating, design hosting and managing a web site (e business) , a forum, blog etc supported by ads, or adlinks to shop sites, ?

No, but you can get a good start at www.godaddy.com

It's on computer maintenance, and I am going to put in a lot more stuff. I was just wondering whether it's good for a start.

http://pctonic.blogspot.com/
yeah, i am not that strong in english…often make complex sentences………..
ok, i will put some comments in the media players category…….

needs more stuff and it needs to b not as boring and put stuff in terms that everyone can understand

I want to import some points from Wikipedia to my blog on compuer maintenance. Is it illegal? I want to copy the entire list, as it is very long and I don't have the patience to re frame it into different sentences and all.

As long as you mention that you've taken it from Wikipedia, then it's legal.

http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License

I would like to be able to delete entries more than, say, nine months old. Would it be possible to provide to the blog owner, in 'signed in' mode, a link to a dated list of blog entries with the ability to select multiple entries and delete them. This would save considerable user time when it comes to blog maintenance.

no. you must do it one at a time.. from the blog itself..