You can get great deals on On30 equipment from eBay and that is, without a doubt the best prices on a daily basis. If you are getting started, you can be up and running with flex On30 track (proper tie spacing and size) from various suppliers or you can simply use any HO track (atlas, Bachmann, Peco, etc etc).
If you have not bought anything yet - take a look at thefavoritespot.com
He is a huge Bachmann dealer out of Texas and sells on his website and on eBay. I have dealt with him for a long time as have many On30 guys I know. Excellent deals, way cheaper than your local hobby shop.
I just completed a small mini exhibition layout (not shelf), but a great track plan to get started with. You can see it here
http://youtu.be/uNt4KlpWWlg on my youtube channel - other videos of it and my On30 stuff as well.
It's a great scale and gauge to get into (or back into modeling), especially logging and mini interests.
A layout with curves as tight as the mini will limit you to Porters and Davenports, but you can incorporate it into a future (larger layout) as I have done. The previous reply dude is correct, don't waste your time trying to convert O standard gauge into narrow gauge or try to run HO trucks.
Now having said that, I scratch build a lot and using HO trucks for builds of rolling stock in On30 is fun and it fits. Also see video on my channel of my box cab that I did where the trailing car is an example of a scratch using HO trucks.