How would I make a start-up script in Mac OS X?

[sturm105]

I'm currently using MaNGOS on my Mac, and every time I want to launch it I have to open up two iTerm windows and cd to the folder, then launch the applications. It's really a trivial task, but I think it would be better if I wrote a script to do it for me. I couldn't figure out where to start, so I thought maybe one of you had one already. If you don't, we could write one together! Here's the commands I need it to execute (in this order.):

Open a session (in iTerm)
"cd /opt/mangos/bin/"
"./mangos-realmd"
Open a second session in the same window as a new tab
"cd /opt/mangos/bin/"
"./mangos-worldd"