Houzz.com overview of preparing to move - comprehensive article does a nice job, but the most important aspect is to have your Realtor coach you through all these steps. So you'll be doing what best fits your home's current market.
Notice step one is to find an agent. I recommend doing that by getting recommendations from people you know and trust. An agent or company's marketing is nowhere near as important as the actual experience of their previous clients.
Once you have the right agent, they should be advising you through each of these steps.
Moving to another city? I might know a good agent where you are headed. Give me a call.