[Haskell-beginners] helper tools for reading haskell source

Hey, Often, when I read haskell code, I would like to know how and where a datatype or function is defined. Normaly I read the code of package, and I then use grep. But when it is not defined in the same package, grep can not help me. Example: I want to know where the datatype Frame and the function windowGetChildren in the wxHaskell odule are defined. I know there is hoogle, but for these it was unable to help me (or I was unable to use it correctly?). So I was wondering, what other tools or methods do you use to "analyse" haskell source? Regards, Nathan