If you read and study this electrical Secrets section you will find your questions answered in more detail for sure. Your questions have been
answered here before.
That said I will make a first attempt to answer your questions.
Here is an article that may help you.
http://tinyurl.com/gbf6r
Assuming your trailer is a small Teardrop with 120V service?
Your Question:
1)The power cords used to hook up to campground power--are they configured male/female or both male ends or what...
Answer: 120V Male / Female standard outdoor extension cord.
Your Question:
2)I assume that the power connection at the trailer is like the gfi receptacle on my patio?
Answer: Assume nothing / Could be GFI or fused panel in your rig. See this example
http://tinyurl.com/g4986 for an idea of how many home made trailers have a receptacle for inlet power. This is where you would plug in the female end of your cable from shore power. Again this electrical secret section has many threads that explain all of this in more detail.
http://tinyurl.com/fng4h http://tinyurl.com/zl4ma http://tinyurl.com/h6gfl
Your Question:
3) 30A shore power cords at West Marine are$$$$$$$$. Any good prices to be found elsewhere--Boaters World etc?
Answer: This is a question with a few answers and solutions. I would suggest that an adapter plug be had for the times you need to hook up to a 30A service using your standard cable with it. Example
http://tinyurl.com/h9ua9 a two to four dollar cost is average for this solution.