One thing what I really want to know, is how do I install those custom scenery things?

Usually the instructions are located on each download's readme, but most CS or custom scenery can be installed by putting the folder where all of the CS files are into Program Files/RollerCoaster Tycoon 3/Style/Themed .....

Nerdygeek has made some great suggestions. If you need more detail you might want to take a look at this post and Alex's following post.

http://forums.rctgo.com/thread-7362-post...l#pid83286

Thank you for all this information! It's really helpfull. I'm always having crazy ideas for building theme parks, and this forum helps me with that. Unfortunatly, I'm really really busy with school, most of the time. I wish I had more time, haha. A well, 10 weeks and then there is summer vacation! Plenty enough time to play RCT! (not the whole vacation tough, haha!)