1.) Start working with him and praying to him. I had a similar experiance, except he didn't speak to me. he looked at me and it sent a surge of energy through my whole body. 'Twas wonderful.
2.) This is always a difficult task. Ask Odin for his guidance and protection when informing them of your newfound religion. They cannot force you to convert to any other religion. That choice is yours and yours alone. If they don't accept your religion, do not get discouraged. Odin and the other gods will be at your side when you need them.
3.) Normally, an alter is required to give an offering. When I offer to the gods, I invoke them and we usually share. But when we don't, I set the meal on their alter and after I feel like they're done with it, I throw it out or eat it.
I hope this helps! If you have anymore questions, feel free to mail me!