HI Mike,
I am a Registered Professional Forester. There are lots of resources on the OWA website and online. 3000 trees is likely a plantation of a few acres. The 1st commercial thinning would involve harvesting every 4th or 5th row. You could start by harvesting every 4th or 5th tree (choose the smallest, or forked/crooked trees), once the trees have closed crowns (bare ground with needles). Leave branches etc on the ground for organic matter and habitat.
yours,
Eleanor