I probably wouldn't recommend training team members on Backtrack. Backtrack is a go-to tool for network penetration testers, but if your concern is the security of your code, you're better served with a license for Burp Suite. Much of what's in Backtrack, including Metasploit, is probably not going to be useful in the "we'll need it every time through the dev cycle" sense.
Wireshark (to analyze traffic coming too and from my website), Metasploit (To make social engineering exploits to make sure my servers arent vulnerable), Mantra Security Framework, Cisco OCS Mass Scanner (For breaking Cisco Routers), SQL Inject, SQL Scanner (Both for finding injection errors). If you master these, you can do a lot of cool things with them. Wireshark is your best friend when things aren't over SSL.
