What kind/How much memory can i install?

Before you ask, my Mobo did not come with a manual as my rig was bought retail and i guess it was just not included in the package. And secondly ive swearcher everywhere but i cant find my Mobo anywhere on any site, not even the manufacturers.

My mobo is apparently an Manufacturer: ECS/Model: Nettle3, 2.1 (According to CPU-Z)

If you need the specifics on the memory already installed on my computer id be more than glad to tell you. Im just looking to upgrade my memory to some DDR3 perhaps and get myself an extra 1GB.

So my question being i guess is... Are there any programs or websites that can help me determine:
What kind of memory can be installed on my computer?
and How much of it Can i install?
and if you manage to find the specifics on my particular mobo online somehow that would be kool too

Any help would be appreciated, thank you one again TomsHardware Forum

Unfortunetly yes, i believe that Is my board... as crappy as it is... but oh well. from the looks of this document i think it may be better to just wait till i make a new comp with a better mobo...

I only have 3GB of DDR2 400MHz memory... you think that will be enough for gaming? (games such as WoW, The Witcher, Lineage 2, Fallout 3)

AMD Phenom 9500 quad @ 2.21gh

o1die, made a pretty good suggestion for being able to play those games. Should get in the mid settings anyways.

Unfortunately this is 1 of those times that having a dual core may have made it more beneficial for gaming, with higher MHz on the CPU.