I've worked in Infosec for over 4 years and have been on both sides of the interview process. I have only a few high level pointers.
1. If you are passionate, show it. If you want to work in the security industry you have to really nerd out on this stuff and not treat it like a day job that "pays the bills".
2. Don't BS about technical answers. If you don't know the answer to something, that is OK. A good interviewer would rather you walk them through the steps you would take to find the answer than completely make one up. Big no-no.
3. I don't know what position you are applying for but you should be expected to know some basics about attack vectors, defenses, security strategies, and general computing. Brush up on your scripting skills while you are at it. Python is my language of choice. Bash scripting is also highly desired.
4. Don't regurgitate a list of tools you know. Pick a few that you have used and explain how you used them..anyone can run an Nmap scan but what do the results mean?
5. Be friendly and approachable. This goes with any job interview but just a reminder.
6. Don't stress it too much. It's impossible to anticipate every little detail of every question that will be asked. Be yourself and most of all, be curious.
Hope this helps! Feel free to PM me with specifics and GOOD LUCK! Hope too see ya at the next con.