Welcome to Pinside!
You will find many useful tips here: http://www.pinrepair.com/em/index.htm
For parts, rubber kits and help with what parts you need contact: PBR - The Pinball Resource
http://www.pbresource.com/
For your first order, call. Steve will set up your account and explain how you pay.
Marco Specialities is another source for parts: https://www.marcospecialties.com/
For post replacements, you may want to check eBay or the “EM parts wanted” thread here on Pinside.
When you replace the rubber, do not double up the slingshots.
Lastly, it’s not a hobby, it’s a disease!