If you want to share a hobby, then quilting will be an excellent one to share. You could very easily work on separate projects or as he becomes more proficient, if he likes doing some aspect of it that you are not as excited about, then sharing a project could be a really fun thing to do.
If you would prefer that he find a hobby that's completely his, model railroading might be right up his alley. Another that he might enjoy would be leatherworking. My hubby enjoys both of these, as well as photography (which he has also done professionally both portrait and car/motorcycle shows).