Here's the stats on your machine:
http://everymac.com/systems/apple/macbook/stats/macbook-core-2-duo-2.26-white-13-polycarbonate-unibody-late-2009-specs.html
Apple MacBook "Core 2 Duo" 2.26 13" (Uni/Late 09) Specs
Identifiers: Late 2009 - MC207LL/A - MacBook6,1 - A1342 - 2350*
It will take two 4GB sticks of RAM Type: PC3-8500 DDR3 Min. RAM Speed: 1066 MHz