If you are running a GUI interface, the GUI configuration should offer a way to do this.
Most desktop environments include a "startup" item in which applications can be configured to run when the GUI starts; it may also be called something like "session" on the menu. Most window managers have a way of configuring applications to autostart when the GUI starts, though it commonly requires editing a text file in some way.
In Fluxbox, it's in ~/.fluxbox/startup. Here's an example from my ~/.fluxbox/startup file:
Code:
# And last but not least we start fluxbox.
# Because it is the last app you have to run it with ''exec'' before it.
xscreensaver& <-----starts Xscreensaver
~/scripts/wallpaper.sh& <----starts a script to rotate wallpaper every X minutes
gkrellm& <----starts GKrellM
keepassx& <----Starts Keepassx
exec fluxbox