Is it possible to send an envelope to someone to review and then once they approve it to sign it is then sent to the signer? If so, what are the steps to complete this task?

Yes, this is possible by creating a Recipient workflow process that uses Signing Order and different Recipient Types. When adding Recipients to the envelope select "Set Signing Order" which is typically a checkbox near the top when adding Recipients, this allows for an order to be used in which the Recipient who has action must complete the action before the next Recipient is notified. So with Signing Order enabled you would, in this use case, add Recipient 1 (Signing Order 1) as a "Needs to View" which allows them to look at the document, but doesnt require action. You could also set Recipient 1 to "Needs to Sign" and use something like an Approve and Decline buttons to allow that Recipient 1 to decide to move that envelope forward (Accept) or void the envelope (Decline) without having to Sign. The second Recipient (Signing Order 2) would be "Needs to Sign" and would be notified when Recipient 2 has action to take (signing) and would take their action of Signing, which when finished would complete the envelope.