Please specify which types of gel electrophoresis (for DNA/RNA or protein?) you were asking. Since DNA/RNA gel electrophoresis is relatively simple, we do do not have such detailed protocols on our site. But, you could find many good protocols on internet, such as http://arbl.cvmbs.colostate.edu/hbooks/genetics/biotech/gels/agardna.html
Fro protein gel electrophoresis, you may search our website by using keyword "electrophoresis" and see if you could find answers that you are looking for.