If you have 2 GB of memory an upgrade to 4 or 6 GB is inexpensive and will improve performance. Buy from OWC (macsales.com) or Crucial.
http://eshop.macsales.com/shop/memory/MacBook/DDR2/
Your hard drive inteface is SATA I (1.5 Gbps) so you will not realize the full 3 or 6 Gbps speed of the SSD but you will see an increase worth the price. Your existing HD is probably deliveing 0.5 Gbps so an SSD or SSHD is likely to more than double that bandwidth. I recommend purchasing the SSD from Crucial. Not all SSDs are Mac friendly.
For less money and more capacity you might consider a hybrid SSD-disk such as the Seagate SSHD. It is a 500 GB or 1 TB disk for under $100 with an 8 GB SSD cache (about the same price as a standard disk). It delivers "SSD-like" performance.
http://www.crucial.com/store/partspecs.aspx?IMODULE=ST500LM000
http://www.newegg.com/Product/Product.aspx?Item=N82E16822178340
The following article will show benchmarks of Seagate SSHDs compared to traditional HDDs and SSDs.
http://www.extremetech.com/computing/150004-seagate-launches-new-hybrid-hard-dri ve-that-closes-the-ssd-gap-drops-momentus-xt-brand