hi! you can submit links here:
http://www.general-files.com/submit/links

I already know about that link, but where can I add a link that includes comments and file sizes, and such things that appear in other file-catalog links?

ok, if you want to add a file with a full description in our General-Catalog, you can do it here (new article should pass moderation):
http://www.general-catalog.com/upload-files

in addition, all download-links will automatically appear in the database General-Files.
this is what you want?

In general-catalog/upload-files, there are 2 fields: Poster and Screenshots, what is the difference? Can I submit both direct links and filehosting links?

"poster" - is a main image of an article, usually its cover.
"screenshots" - are all other pictures for that (if exists).

yes, you can submit both types for links.

I am submitting unique posts but no news appeared in My news section. Why this is happening? Can I become a verified poster.

new articles are usually checked by our technical support, but now we have temporary delayed it.
but i approved your posts by manual mode.

we are preparing a mechanism of "verified posters" to release soon.