So, i recently started a new comic strip on this site. after all the editing was done on my comic, i was disappointed by the outlining of the characters and objects

process is drawing, inking, scanning, and putting it into Photoshop. in photoshop i used to Posterize effect to make the lines more noticeable, but it also screws them up.

if there's a better way to do that, i'd love to know
thanks

The best thing to do is link to an example of your work so we can give you some advice.
But generally I wouldn't posterise to make the lines more prominent. Adjusting the brightness and contrast is a really simple way to do that without ruining everything. :)
But there are lots of other ways too.

oh sorry, here's a link to the comic
http://www.drunkduck.com/Insert_2_Coins/?p=41092

Could try the pen tool like what everyone seems to do.

Or double your lines, keep 'em transparent and just color below them like I do.

Double the layer click "Channels" were the layers window is. Click that circle sign on the bottom then hit Delete. Clean lines! Then Edit>Fill> and use black 100% normal preserve transparency will make them darker.

Also, what format are you saving it in? Maybe .png would work good for ya.