wood frame foundation

I inspected a home with a wood frame foundation, my first such home. Any advise as to what to be awaire of?

Thanks in advance for your help.

http://www.nachi.org/permanent-wood-foundations.htm

More info:

http://www.pwfs.com/
http://www.woodfoundation.com/
http://www.biewerlumber.com/prod_pwf.html