Yes, the whole reason for supports on a roller coaster are to hold it in the air. If they didn't touch, what good would they be? Instead of directly connecting them, use another custom scenery pack called CoasterJoe's B&M Connectors (
Link) to place between the support and the track. It makes it easier to connect and makes it more realistic.
For stations, you should try to use a custom tracked ride, or CTR. Usually with these, the station track pieces will look like block brakes, without the loading platforms. If you use these, you can create custom stations that look a ton better. I've created a tutorial and also a pack of station templates that you can use.
Tutorial -
https://www.youtube.com/watch?v=8hMk0WL5X3Q
Station Pack -
http://rctgo.com/downloads/view/4578
To see how far apart to put the supports, refer to real-life images of roller coasters. I usually do 3.5 to 4 tiles apart, but it also helps to imagine your ride is a miniature model that you would build on a table. Lay out the supports in your head that are spread out as much as you can without it wobbling or even falling over. If that doesn't help, just place them however it looks right.
For a tutorial, try looking up Silvarett's YouTube channel. But it's actually some pretty simple basic rules. Start out with each support as a single vertical column. If it's really tall, try adding a diagonal to make it a V-frame (1 diagonal 1 vertical). If there is track in the way, you can change the slopes, or change it to 2 verticles. Note: For lift hills, I usually use 2 verticals, you can also add a horizontal to make it an A-frame. Shorter supports don't need re-inforcements, unless they are on a low-to-the-ground sharp turn. In that case make them all tiny little V-frames. Also don't be afraid to tilt the supports a little. Not all of them are 90 degrees straight down. For special elements, such as loops and corkscrews, use the pictures below. In the pictures I'll show you examples of all the support types I mentioned respectively.
V-frame (2 diagonals):
V-frame (1 diagonal 1 vertical, with exception of the first support)
Low-ground turn:
Angled/tilted support:
Loop:
Corkscrew (Tripod support)
Zero-G roll:
For other references, try Wikipedia and Google images. I have shown mostly B&M style roller coasters, I assume that is what you are asking for. Enjoy!