About.com is an excellent site where you can find plenty of crochet pattern tips, tricks, and resources. The host, Sandi Marshall, has even put some of her own crochet pattern charts online. You'll notice that on the right side of this blog I have place a feed for some of her current articles, but if you are looking for great Valentine's Day crochet pattern charts, then click here.
Valentine's Day Project
This project has instructions for making cross stitch designs on top of the crochet underlayer. She also has a list of other Valentine's Day crochet patterns available on the site. But if you are looking for basic information regarding how to crochet, then you will want to visit her part on the site where she teaches Basic Crochet Stitches.