Samples are a great way to try a product before you buy.
Below I've listed some of the companies and samples they supply very generously.
List correct as of April 2014 

Baby Love - sample nappy
Australian Baby Hands - free baby sign language chart
SIDS - downloadable brochures
Texta Kids Club
IGA Kids Club
Gaia - sample pack of belly butter, sleep time bath, hair & body wash, skin soothing lotion, baby moisturiser
Johnsons & Johnsons - sample pack of breast pads, mini bottles of sorbolene, moisturiser, bath wash & baby powder
Nice Pak - Join the Baby Club for sample and much more