I've got a few questions about : "how can I make my site be well classified" 1. I've read that people can use the <metaname="author"> to boost their classification by putting keywords in it and also their URL. Is it really possible, I mean, Isn't it considered as a kind of spamming? 2. I know that major SE used spider to classifed the sites, but is there another way? I mean, a human intervention or else. How does it works, for instance, when Lycos recommands a site. Do I or can I pay for such promotion?
Well, it looks like you have a bit of reading ahead of you Clair. Getting well listed in search engines is a bit of an art form. Most of the people that read here, do this for a living - so, there is a bit to it.
Meta tag tricks like you mentioned don't work.
Most of the big se's (altavista,google,Inktomi, Hotbot, Lycos, Excite) all use Spiders to download you site and 'index' it and do not take money for listing your site.
You can pay a search engine goto.com to list your site where you bid on keywords and then pay for the actual users they send you (ppc: pay per click). Yahoo and Looksmart both take $199 just to 'look' at your site, but they will often list it or give you a reason that they don't.