Yes, especially if you use a dSLRs the photos need a bit of sharpening unless you tweaked the in camera processing settings. Use Photoshop to resize, make sure you use Bicubic. Then use USM.
Launch Photoshop, when you resize by default the resampling option is Bicubic. USM = Unsharp mask, you never use before meh? Do a search, got quite a few guides on how to use USM.
Thanks, never use before leh, else I won't be asking this question. I'm using those software given by canon when I purchase my cam, do those software have those features?