I want to ask a stupid question but ... i never writed a blog Can i write about any subject cars, television, money, traditions all in one blog ? or the blog must have one subject ...i'm interested because i want have a good ranking if i write something ...(a good position on search engines)
yeah just about anything it called "blogging" just blog about anything I suggest you to write for a low competition niches and those with high paying keywords
But i will rank good if today i will write about icecream and tomorrow about free books (example) ? i must submit every article somewhere ?
If you're writing something really rocking, certainly you'll get ranking as well! Just start it, do your best at it and see how it works!
Ok , i installed Wordpress Adman plugin, what i don't understand is what robots.txt file to use i saw many but still don't know which one to use ...( good for seo, i'm interested to rank good every page for that keywords ) and the "ping" problem ...
I'd suggest you don't worry about page rank and seo at the moment. Just figure out how to run your blog and what you want to write about. Then do it well. Once you've got that under your belt, then you can focus your energies on SERPs and PR.