WHAT IS TUBELESS
Tubeless - i.e. No Tube..same as your car tires. Just the Tire which seals onto the rim.
WHY GO TUBELESS
The idea is to reduce rolling weight. However using Specific Tubeless Tires sometimes do not necessarily mean that you reduce the weight of the overall set up. This is because the reinforced sidewalls of the tires can add to the additional weight of the tires overall
EG - I'm running Kenda Nevagals 2.1 UST. Tubeless tires...but very heavy, but this is due to the make. I love the grip, therefore I put up with the weight. (if I got to 1.95s, I can easily drop 1lb of the weight of the bike...and that's a lot)
To get good weight reduction, use the combination of "Tube" version of tires, and get Stans No Tubes conversion (http://www.notubes.com/). Basically it converts your "tubed" wheelset to a tubeless set up. Therefore, you reduce weight(i.e. no tube), and you get the bonus of a lighter tire in the form of a non UST tube tire. Make sense? You can get this from Hup Leong Bike Company in Singapore. Not sure if anyone in Malaysia stocks them. Do check to see if you wheelset can be converted. Some continue to leak air, so check first lar.
WHATABOUT PUNCTURES ETC
Use sealant. I've got Stans No Tubes sealant in mine, and essentially no punctures except the one time when I put a micro tear on the border of where the tire sealed against the rim. No chance there lar.
If really koyak, can always put a spare tube in to get you home.
TIRE PRESSURE
Tubeless also allows you to run very much lower tire pressures. As there is no more tube in your tire, that means no more snakebites..i.e. where the rim "bites" the tube because of lower pressures. Why lower pressures ? It allows more surface of the tire to eat the dirt that you are riding on = more friction = more grip.