If you're new here, start with the Tendermint Intro.
To start building an ABCI application and integrating with Tendermint, see the App Development and App Architecture guides.
To learn more about running the Tendermint software, see the Using Tendermint Guide.
To learn more about Tendermint's various pieces, check out the Documentation. For a deeper dive, see this thesis. There is also the original whitepaper, though it is now quite outdated. You might also be interested in the Cosmos Whitepaper, which describes Tendermint, ABCI, and how to build a scalable, heterogeneous, cryptocurrency network.
For details on how the software has changed, and what changes are in store, see the Changelog and the Roadmap.
If you're interested in contributing, see our Contributor Guidelines
The Tendermint Software Ecosystem contains many example applications and related software built by the Tendermint team and others. Check it out for some motivation and inspiration!
See our Community page for more ways to collaborate.
You can also get in touch with the team.
Most importantly, enjoy!