I'm still in Sydney and still looking for work so I thought I'd distract myself by giving the best tips and advice I've learnt from a few weeks in Thailand.
In summary I'd say that you should fly to Bangkok and stay on Koh San Road to start. Maybe stay about 2-3 days after you've done some tourist stuff to soak it up.
Ban Yan Tree Hotel is a MUST. It's a roof top bar right in middle of the business district of Bangkok open only after 6. I seem to remember you have to wear trousers and shoes but have one drink there and you'll be amazed.
Go to Chang Mai – do the trekkiing with long necks and rafting. You should also visit Roof Top Bar (cool backpacker place). watch a Muay Thai boxing match as it's cheap here, go to Pai – spend maybe 3-4 days here more if you like, get a map rent bikes explore, caves, waterfalls, retox bar. ting tongs and white water rafting, depending on the season.
From Pai I'd say you should get a bus to Laos and go on the Mekong SLOW river boat ride.
Go to Luang Prabang. Take 1-2 days to visit some amazing waterfalls and do some trekking here. Make sure to go to a Laos BBQ and go to the bowling alley at night.
In Vang Vieng stay maybe 6-7 days. The tubing and waterfalls are amazing.
Then head to Vientienne. Now from here we went back into Thailand to Khai Yao National Park which was cool but if you wanna do Vietnam and Cambodia it might be a idea to head to Hanoi, go down the east coast of Vietnam then back into Cambodia and back into the south of Thailand. I heard Angor Wat Temple is amazing in Cambodia. There's also lots of Laos that we didn't see too. 3,000 Islands is supposed to be good.
After the national park we went to Koh Tao diving, which was awesome. We never did Koh Samui but thats supposed to be a proper party town! You'll have to look when the Full Moon Party is on and time the trip to Koh Tao + Koh Samui with that because Koh Phagnan is near these two islands.
From Koh Tao we went to Krabi (don't bother) but you have to go there to get to Railay (deffo go Tonsai Beach) then Phi Phi (longbeach is cheapest) then go Koh Lanta for a day or two (rivera resort).
Haggle everyone most of the time and you can get pretty much everything cheaper.
Watch out in Bangkok as tuk tuk drivers try to rip you off left right and centre! Tuk tuks are fun but you're better off getting taxis on the meter they work out a lot cheaper. If a tuk tuk driver offers to take you to clothes shops it will be to get a fitted suit so unless you want one just get them to take you straight to where you wanna go, or you could end up paying a lot for it.
Keep all your valuables on you when travelling on buses, most of the time they have kids in the luggage holds going through bags looking for stuff to rob!
Enjoy a smoothie everyday dirt cheap. I recommend peanut milo's mmmm and obviously lots of buckets!!
Have fun Thailand and Laos are both absolutely amazing. I've just had the most incredible few months of my life!