I am not sure of what kind of games are the games available on this website and would like to know if any are decent point and click adventure games. The kind like quest for glory or even secret of monkey island

The 1st & 2nd Simon the Sorcerer games are similar to the graphical style of Monkey Island.
So are Beneath a Steel Sky and Lure of the Temptress and both of these are free.

Pointy-clicky. I don't think it's a complete list, but it's a start.

He :)
I actually have all of those games...

There is also Teen Agent for FREE on GOG.com.

I'd point you towards Broken Sword 2. It's very well written ,and it's somewhat akin to what playing a Dan Brown novel would be like. It's also pretty funny if you have a warped sense of humor.
If you want a taste of what the writing and humor is like Beneath A Steel Sky, and Lure of the Temptress are free on here, and are by the same developers as Broken Sword 2!
Hope this helps!

There's a great game called "Ben There, Dan That" that's available for free (google it). If you like it you could continue by buying the sequel "Time Gentlemen, Please".
:)