I've just started a bit on this myself. Began with belts which were simple enough. Then I went to a workshop at a local leather artisan here in Singapore, followed by tons of reading online in forums and watching youtubes. Have made some small card holders and a passport holder as a trial. Moving on to watch straps next. :) It's fun if a bit time and resource consuming.
I get most of my tools from ebay. A good seller is goodsjapan. Good tools for a reasonable price. As for hides, I get from the aforementioned leather artisan.