kernel compile trouble after upgrade

[Jan Willem Stumpel <jstumpel@planet.nl>]

a) After upgrading from woody to testing, I could not compile
   any kernels at all. All sorts of error messages appeared.

/usr/bin had:

lrwxrwxrwx  1 root   root      7 Jun  1 14:50 gcc -> gcc-3.3
-rwxr-xr-x  1 root   root  74088 Mar 18 00:16 gcc-2.95
-rwxr-xr-x  1 root   root  74056 Apr  8  2002 gcc-3.0
-rwxr-xr-x  1 root   root  80652 May 18 13:00 gcc-3.3

b) After changing the symlink to:

lrwxrwxrwx  1 root   root      7 Jun  1 14:50 gcc -> gcc-2.95

   I could re-compile my old kernel, 2.2.18pre21.

c) After changing it to

lrwxrwxrwx  1 root   root      7 Jun  1 14:50 gcc -> gcc-3.0

   I could compile 2.4.20.

-- is this normal (so many different gcc's)?
-- isn't this a PITA?
-- what documentation should an ordinary user have read, in order
   to know about this?
-- what should I leave the symlink at?

Regards, Jan