and can u guys pls explain how do i install them?where do i extract them?and how should i return to default skins if i want?

I dont know how to get to default, but dont get to default, because its hard and not fashionable.
to install the skins simply extract the same folder name like cstrike o cstrike
http://www.gamebanana.com/tuts/53 there

yeah that would be really  highly appreciated nd can i use ct outfits if im a t? just to fool them lol

The skin would only affect how YOU see people. It doesn't change how other people would perceive you, unless it's server skins.

i extract the skins into the cstrike folder but nothing changes -_-

Did you read the tutorial that mar_heave posted?

i extract the skins into the cstrike folder but nothing changes -_-

when you extract, it should OVERWRITE something... if it doesnt overwrite, then you install it in the wrong folder...
dunno how to explain this one, but inside the Counterstrike-Source\cstrike\ folder, there are a lot of folders like materials, models, and sounds...
these are usually the 3 folders that's used to change the skins...

NOTES: inside the materials folder, there is also a models folder, so pls do NOT confuse them between models inside the cstrike folder and the one inside the materials folder
HINTS:try to look at the type of the file..the models folder inside the cstrike folder have .mdl extension, while the one inside the materials folder have .vmt or .vtf extension
          if you are NOT SURE of what you are doing, be sure to backup the whole css folder in case you messed up everything

Did you read the tutorial that mar_heave posted?

and yeah, try to look at the one that mar_heave posted..
ive take a look at it, and imho its very useful...

ooooooook o_0