Joining granny squares...

Terri, and everyone, thanks for your kind comments about the charity ghans! In answer to questions, I join my squares using a whipstitch. If you're not familiar with this method, using a large-eyed needle and yarn, I hold the right sides of 2 squares together and stitch into the back loops only (BLO), joinging them so they line up evenly. I also tug the yarn after a few stitches, so you can barely see the joining, even from the back. Here's a pic of the wrong side of one ghan:
I don't have the name of all the helpful sites that can walk you through this, but a great place to start with any crochet questions is the Lion Brand Yarns web site. By googling "crochet" you can also get lots of help.
Important: to begin the joining and to end it, I weave in the yarn forward and backward so it locks, and won't come out. Washing the ghans before giving them away is also a must for me. It's a great way to discover any ends that you may need to secure more tightly...in addition to helping to get rid of any fur or doggie drool from my German shepherds!