Seed germination

Hey guys, I've got a question...so, I'm trying out growing for the first time. I just can't get my seeds to sprout. I put a few in between 2 sponges and a few others in between a 2 layers of a couple tissues each and checked them every day, but no dice. Its been about a week for the ones in the moist sponges and a few days less for the ones in between the tissues. I keep them in my closet in between two bowls to keep everything dark. I feel like I'm doing everything right, but its not working.

I'm thinking that maybe I'm giving them too much/too little water. Can anyone help me out with more specific directions for watering seeds? All I hear is "moist but not too wet", but I've got nothing on which to judge between the two.

thanks for the help
~CP