If you are a newcomer and would like to learn more about the Cosmos SDK, this **[intro](./intro/README.md)** is a good starting place.
### SDK tutorial
If you like to learn by doing, you can follow the **[SDK application tutorial](https://github.com/cosmos/sdk-application-tutorial)**. It showcases how to build an SDK-based blockchain from scratch, and teaches you about the basic principles the SDK in the process.
## Use the SDK
The following sections contain the information you need if you want to build a fully-functional SDK-based blockchain:
>*NOTE*: We are currently working on improving the docs. Some info might be missing. If that is the case, try the Cosmos [Forum](https://forum.cosmos.network). Failing that, [open an issue](https://github.com/cosmos/cosmos-sdk/issues/new).
- [Introduction](./intro/README.md): Contains introductory high-level material on the Cosmos SDK.
- [Gaia](./gaia/README.md): Contains all documentation related to the gaia application (current name for the Cosmos-Hub).
- [Clients](./clients/README.md): Documentation about SDK clients like the SDK Command-Line interface and the SDK Light-client.
- [Specifications](./spec/README.md): Contains SDK and modules specifications.
If you are reading this on the Cosmos Website, please know that you can find more information on [github](https://github.com/cosmos/cosmos-sdk/tree/develop/docs). Also if you find any issues with the documentation please [*open a Pull Request*](https://github.com/cosmos/cosmos-sdk/compare?expand=1), or at least [*open an Issue*](https://github.com/cosmos/cosmos-sdk/issues/new) to update the docs!
## Join the public testnet for the Cosmos Hub
To install the latest version of the `gaia` application and join the public testnet, **click [here](./gaia/README.md#join-the-cosmos-hub-public-testnet)**
