Track bed

My trains run on foam and Brennan's Better Ballast with no problems.

I used Scenic Express foam with Atlas track and like it a lot. I also used Atlas track screws.

Can't beat flexxtrack 

I used woodland scenics foam track roadbed.  Just glued it down and held it in place with straight pins until the glued dries.  I have friends who used cork also glued down.  Once ballasted they pretty much look the same.  I happen to get my roadbed on eBay at a good price which is why I went with it.   You can buy a small section of each and try the both out and see what you like.  I don't think you can go wrong with either method.

Cork is probably the cheapest, but AFAIK it still comes in 2 pieces, so it arguably takes longer to install. IMHO, foam with beveled edges looks better if you don't intend to ballast. It arguably lasts longer too, though once you do ballast, that probably doesn't matter in the long run. It probably doesn't matter much either how you attached it, but I believe most use glue. One of the biggest problems that's been mentioned with foam is a tendency to attach track screws too tightly causing unevenness. If you're concerned about noise, you also have to consider how well both hold track screws so you don't have to go through to the plywood underlayment, if that's what will be under the roadbed. That's one reason many add a layer of Homasote, so they don't have to go through to the plywood and transfer track noise.

Midwest cork.  With a utility knife and disk sander it can be altered to fit most everything associated with track and accessories.

To all who replied to my post, thank you.  It seems there are numerous ways to get the job done.  I will see which method works best for me.

Again, thank you guys for your answers.