Re: what drinks or foods have electrolytes in them...
Gatorade has electrolytes. I used to have an electrolyte imbalance, and this is what the doctors would give me to drink whenever I had blood tests to do.
In general, the electrolytes that you lack when you need electrolytes after a good workout are usually just potassium and sodium. Bananas are good for potassium, as are potatoes and really a lot of vegetables.
Other electrolytes are magnesium, calcium, bicorbonate, chloride, etc.
Hope that helps a little!