gcc and linux newbie's question

["Hankel O'Fung" <master at polyu dot edu dot hk>]

Dear all,

[Please also reply by email. Thanks.]
According to http://gcc.gnu.org/install/configure.html ,

  "We use srcdir to refer to the toplevel source directory
   for GCC; we use objdir to refer to the toplevel
   build/object directory."

1) Is "source directory" the directory where I place the
   decompressed and unpackaged gcc bzip2 files?

  "... when configuring a native system, either
   'cc' or 'gcc' must be in your path or you must set
   CC in your environment before running configure.
   Otherwise the configuration scripts may fail."

2) Does it mean I should set those things before configuration?
3) How to set 'cc' or 'gcc' or 'CC'?

Thanks in advance.
--
Cheers, Hankel

http://www.acad.polyu.edu.hk/~master