I've been advised that if I buy rice land to build on, I need to fill it before the rainy season, and then wait at least a few months until after the season ends to let the ground settle, and then begin the building.
Is there any way to speed up the process? For example, if I bought the land this month, fill it, have water trucks come out a couple times a week and water the area and have a road roller go over the area a couple times a week? Maybe do it for a month or more?
I never thought I would consider building, but it seems that ready built houses with a little bit of land around them, out in the country, are few and far between.

As you fill the land compact it. For every 12 inches of land fill you should compact it. Keep repeating this process until you get the desired level. You will have to contract with someone to do the compacting. Some companies that provide the landfill can also provide a bulldozer and a roller.
Also use 7 meter concrete piles driven into the ground. Build the column foundations on top of these piles.

If you do not leave it to settle for a few years then piling is essential,around 50,000 Baht for a small house.

That's piling for a two storey house.One storey does not need piling.

The rice land will be situated on the Alluvial flood plain of the nearest river. Its the soft alluvial material (black mud) that will be subject to consolidation. It may be worth hiring an excavator to remove the soft alluvial material. The alluvium will be overlying the red Lateritic soil which is more than suitable founding material for a one or two storey structure.

Once the alluvium (mud) has been excavated, fill the hole with suitable material and compact using a vibrating or dead roller in 300mm layers, up to the desired formation level. The fill material is generally the same laterite soil that you need to dig down to.

Piling will not be required if you use this method, but you will need to carry out a trial pit with the excavator to see how deep the alluvial material is. If the mud is greater than 1.5m I would probably opt for piling (depending on the area you want to excavate).

Another alternative to piling though is to surcharge the mud to quicken the consolidation process. This can be done by placing (not compacting)0.5m layers of fill material onto the mud over a period of weeks. Leave each layer for 2 or 3 days. The more layers you put on the quicker the consolidation process. Youve got to be carefull not to put the layers on too quickly as you could create a mud wave.

Once youve determined how thick the mud is I can advise you on which is the most suitable method to use.

Thanks for all the info.
I'm still considering whether or not to undertake the project. I've heard nothing but horror stories when it comes to building a home here in LOS. Maybe I should start a new thread. But, I'd like to hear of any positive experiences people have had building here.

Sorry, I cannot help you on that one.