Freshwater fish and the aquarium

Question
Hi Chris this is Lisa again. Almost all of my fish have died I only have a very few left. Just incase these die too; I DO want to start over with new fish. Since you seem to know about fish. Can you tell me what fish I can put together and which ones to stay away from.
 In a matter of less than 24 hours all but 5 fish have died. I have a fan tail gold fish, 2 head/tail lighted fish, 1 angel fish and a molly left in my tank. The molly seems to be aggresive so it might go back anyway.
 But if I start over is there anyway you could tell me step by step or give me a guide on how to correctly set up my tank and advise on what fish to put in my tank and how many.
I love to watch my fish in my tank but am getting frustrated with it. The not knowing part. The people at the pet store I think are just telling me (from what you are telling me) the wrong things just to make a sale. And to me that is not fair to the fish.
 Chris I am desperately asking for your help with everything I need to know about keeping a successful fish tank.

Answer
Hi Lisa;

I'm so sorry this has happened to you. It is far too common I'm afraid. You are right, it's usually all about making a sale. VERY sad for the fish.

The goldfish needs to go back too, or at least get him a 10 gallon all for himself. He needs much cooler temperatures than your tropicals and he is a messy guy all by himself. If you want to keep two goldfish so he has a friend, get a 20 gallon. To help you with the rest of your guys I need my memory refreshed on your setup;

What size tank is it?
What kind of filter system?
How long has it been set up?
How big are the fish that are left?
How many inches deep is the gravel at the bottom of the tank?
Does it have live plants?
What other decorations?

If my question load is maxed-out, write back to me directly here;

chrisrmail@yahoo.com

At Your Service;
Chris Robbins