Some great starting points for developers are our Developer Docs and Developer Forum. We have several team members who are quite active in the forum and existing threads that you may find helpful.
Our DFINITY GitHub has many repositories for getting started, including the Motoko base library, where we will be releasing even more code and documentation in the future.
You can also check out a list of developer resources, which includes backend documentation, code samples, and mobile device app suggestions.
For more guidance on where to begin, check out the Internet Computer Wiki.