standby page while developing

I am developing a new project and sent out some emails to check the idea with potential customers. The project is still in development, there is nothing I can show them (yet).

I would like to offer visitors a page saying that we are working on developing it and ask them for an email address to keep them informed about how it goes, announcing them when we get into alpha testing and so on.

I am very new in wordpress. Could someone point me in the right direction if the topic was already discussed or help me with a pragmatic solution?

thank you