Every hobby will have its own specialist directory website, many of which will be run by amateur enthusiasts as opposed to businesses. It’s well worth getting a link on these sites and you’ll find that most will include your site within a few weeks of you submitting your information.
The way to find the best directories is to use search engines. In the search field type in the sort of key words that you would expect that visitors coming to your site would use. The search engine will then suggest a number of sites and you should go through these and pick out any directory sites. Obviously if they’re easy to find via search engine they’re worth having your site listed on their directory.
Many will insist that you post a link from your site to theirs before they will consider listing you. If this is the requirement then make sure you do add their details in your links section before registering.