Okii So, This Is The Map :) 
The Bit At The Bottom wheere it says Travel To: It will be different where u r...i think 

My Fav Place Is The Cemetry, You Can Earn Loads Of Credits:
If You Kill a..
Zombie You Get                  50 credits
Tough Zombie You Get      100 credits
Undead Dog You Get         120 credits?
Ghost You Get                    200 credits 
Dark Zombie You Get        1,000 credits

I Think Thats Right :) But The Dark Zombie is VERY TOUGH!! I Havn't even found 1 yet ;)

If You Go To Fishing City You Can get Credits By Fishing. 
If The Fish Kinda Stands Up And Has *Bites* Under It's Name CLICK IT for credits
Golden Fish                450
Red Fish                     80 
small yellow 1            50