To become a signer, you first need to appeal to shareholders to vote to increase your reputation. You, in this case, actually refers to your BlockShares public key you wish to use as your reputed signer identity.

I would recommend starting a new thread in the B&C Exchange section of discuss.nubits.com where you explain all the reasons why shareholders should vote for you as a signer.

Reputation voting will start once the protocol switch to 4.0 is complete.

Assuming you have success persuading shareholders to vote to raise your reputation, then you will need to decide which blockchains you wish to support. Only the Nu, B&C and Bitcoin blockchains will be supported at first. Let's say you decide to be a signer for only the B&C and Bitcoin blockchains, but not Nu. In that case, you will need to run a full Bitcoin client in addition to your B&C client. To have high availability, you will need to rent a VPS or dedicated server. You will need to configure your B&C Exchange client to work with your Bitcoin client. You will need to set up and back up wallets that you will use for signing.

Once you have your server or servers set up, you are ready to publish your deposit public key list for BlockShares, BlockCredits and Bitcoins. We will have an RPC that will allow you to do this. These deposit public keys will be consumed by exchange users, so you will need to publish new ones from time to time.

Everything else is automated. On a daily basis, you don't need to do anything except ensure your B&C client and Bitcoin client continue to run and communicate with one another. Signing and validations are all automated.