If you're using a stock kernel, everything should be okay.
In addition to the kernel support discussed above, one of the following userspace components may be necessary for the proper functioning of your webcam:
libv4l-0 (see the 'wrappers' section of its README)
mplayer - Can be used to view webcam video by invoking mplayer tv://
xawtv - A suite of video4linux related software, which can be used to view webcam video.
cheese - "Cheese uses your webcam to take photos and videos, applies fancy special effects and lets you share the fun with others."
camorama - Hasn't been updated since 2007, but it works as a basic, simple webcam viewer.
motion - Motion detection using a webcam.
amsn - "aMSN is a free open source MSN Messenger clone" with "webcam support".
ekiga - "Ekiga (formely known as GnomeMeeting) is an open source VoIP and video conferencing application for GNOME."
kopete - The KDE instant messaging client - supports video for various protocols.
More applications are listed here.
Sometimes, webcams include a microphone inside. Check input level with a mixer:
Individual camera / chipset resources
pwc et pwcx (french)
ToDo : synchronize with the french page