Replying to Park Building Advice Needed

I'm planning on using my spare time this summer to build my own park features at my house this summer. I live on a farm with plenty of hills, so I figured I'd give it a shot. First question- Have any of you ever had experience with building wooden features like they have at Carinthia, and if so, I could use some advice/suggestions. Second- Where do you all think would be a good place to get some actual rails or PVC that wouldn't be expensive? I appreciate any help.