Since it's not quite possible to buy comics where I live. Any advice where can I read it online? Interested in Deadpool, Harley Quinn.

edit-they're moving to a new server. it's taking a while to upload all those comics.

[link]

their site is currently down, but you can try following them on facebook for updates. the site admins are working to bring it back up again. marvel, dc, vertigo, etc.-all for free

It would be great if you could support the comics you like, but you could always go to Kickass.to(known torrent website, needs program like qbittorrent).
Just type in the name and probably CBR as well and you'll find it for sure.

If you're willing to pay (not to sound guilt-trippy, but it's awesome to support the industry) [link] has an enormous collection with current and back issues of a ton of comics, especially from the Big Two. Plus, people generally rate the issues. Deadpool and Harley both have their own respective solo series right now, so you're in luck.

You can get digital comics - [link] - though not as good as the "real thing," I relied on sites like this for years when living outside of the USA and couldn't get the stuff in person.