N scale signals / crossings

I am relatively new to the hobby and would like to install some crossing lights and some target signals on my railroad. I see many products out there, but don’t know what is required to drive them. Can anyone recommend a website or some publication where I could learn what components are required to install a signal and how to wire it?
Thanks in advance

i am going to install signals on my own n scale layout but i havent settled on how i am going to do it. i was going to use electronic train dectors that detect current flow when a loco enters a block along with relays to control the signal aspects plus other functions. i am also switching to dcc soon and i might use that system to control ths signals. i would like to have them work as close to prototype as i can get them. i was a signal maintainer and can design circuits that i need using relays but electronics is something i’m not too familiar with.

This site may help:

http://www.sunrisenterprises.com/