Welcome!! I remember my first quilt well...I almost quit the craft, but I sure am glad I didn't!!
Regarding your rulers and rotary cutting - do you have the rulers with the non-slip backing on them? You can purchase them (they are usually green) with the backing made into them, or you can purchase the backing separatly then cut and stick to the backs of your rulers to keep them from slipping on your fabric. These links to joanns will show you the non-slip backing you can purchase for current rulers or the non-slip ruler(s) you can purchase with the non-slip stuff "built in"!!
http://www.joann.com/joann/catalog.j...RODID=prd17402
http://www.joann.com/joann/catalog.j...&source=search