I've secured a buyer for my condo (Thai) and I will go with him to the land office to transfer the property over to him. I'd like to know what I can expect during this process since i don't have representation and will be alone.

He say's he's bringing a cashiers check for the entire amount of sale...so do i have anything to worry about?.....can I sign and just walk away with a good check?

I do not know if Thailand distinguish between a cashier's check and a bank draft as they do in my home county where a bank draft is guaranteed by the bank but not a cashier's check. I suggest you find that out first so you get your money and not just a piece of paper.

It will only cost you about 5-7,000 baht to get representation. It is well worth it if this is your first time. Quite honestly it is worth it just to avoid half a day at the Lands Office. If you wanted to, however, you could go with your rep for the experience.

You do not need a lawyer. Most "law/legal offices" (the ones that also deal with visas, work permits etc) will do this. Some property agents will provide this service. Mostly this is for their clients, but might do it for other paying customers.

Take my advice - get help. Once the chanote has the change of ownership recorded you have not got a hope of getting your money back if there are any problems.