Permanent magnet questions

Im looking to do some projects with permanent magnets.

I dont have access to a gaussmeter and i'm wondering if there are any sites that have representations, descriptions or formulas for the field strengths of ferrite or neodymium magnets.

Also i need to learn about how magnetic fields from permanent magnets interact with each other in attractive and repulsive situations containing mulitple magnets.

Im guessing im going to have a lot to learn as I have no formal physics education.

Any help enabeling me to understand this concept would be appreciated.