Its great to be able to use your own phone. True Mobile only requires you buy their SIM card $2 in 2014, plug it in and sign up / prepay for a data plan / time block.

It’s a good idea to have at least 3,000 baht on-hand either with you for incidental immediate expenses the first night.

They have a kiosk at the BKK airport right as you exit the international gate to meet your friends, so take advantage of it while you’re there.