Google describes how to set your email address to forward to another account in the help article Forward mail to another account. The instructions below simply add some screenshots to the process.
From the inbox of the account you want to forward mail FROM, click the “gear” icon in upper right corner and choose settings.
When you arrive at the settings panel, choose the “Forwarding and POP/IMAP” tab. Click “Add a forwarding address,” enter the address you want to forward mail to, click “proceed” when asked, and then click “OK.” This will send an message to that address requesting permission to forward email.
Once you’ve completed this step, a new line appears in the Forwarding section enabling you to verify that it’s OK to forward mail to that address. You must click the link in the message (at the address being forwarded to) in order to give permission. (Or, you can also paste the confirmation code in that message into the box and click “verify.”)
Once you’ve verified the address, you now need to turn forwarding on and select what you’d like to happen after the message is forwarded (just leave the message in your inbox; mark it as “read,” archive it, or delete it).
Last, don’t forget to scroll down and click SAVE CHANGES.