Fabrics come in different widths -- most "quilting cottons" are in the 42-44" width range. 1 yard would then be a piece 1 yard long by the full width of the fabric.

Amounts of fabric you'll need will vary depending on how small the blocks are, the shape of the blocks, and the finished size of the quilt.

Here are some patterns and estimates of yardage for the quilt top -- remember you'll need fabric on the back, too:
http://www.geocities.com/quiltfrenzy/
http://quilting.about.com/od/quiltpatternsprojects/tp/easy_quilts.htm
http://www.freequiltpatterns.info/QuiltCategories/FreeEasyQuiltPatterns.htm