Since Internet was born on UNIX machines, you find plenty of nice and easy-to-use applications under Linux. Here are just some:
elm or pine to handle your email; both
programs have on-line help. For short messages, you could use mail, as
in mail -s "hello mate" user@somewhere < msg.txt. You may like programs
like xmail or some such.
tin or slrn, both very intuitive and
self-explanatory.
ftp, ask your
sysadm to install the full-screen ncftp or a graphical ftp client like
xftp.
netscape, or xmosaic,
chimera, and arena are graphical web browsers; a character-based
one is lynx, quick and effective.