Use "echo $path" and "echo $PATH" to see what your execution paths look like. If you need more directories added to your paths you should create this file:
~/Library/init/tcsh/login.mine
And in this file add the new items to your path. Here's what mine looks like:
set path=($path /Developer/Tools /usr/local/mysql/bin .)
The last item means "search the current directory" which is sometimes useful.
You may also want to create these files:
~/Library/init/tcsh/aliases.mine
~/Library/init/tcsh/environment.mine
Set your aliases in aliases.mine and your environment variables in environment.mine.
For environment settings that apply to your desktop session (i.e., all GUI-based applications) you should create the file...
~/.MacOSX/environment.plist
...and populate it with key-string pairs for the environment variables you want. For more about this see Apple's page on the subject:
http://developer.apple.com/qa/qa2001/qa1067.html