If you want to scale out using a replica-strategy you really want to have the most recent version of PostgreSQL. It made things like log shipping pretty much an automatic experience. It still has rough edges, but the latest version really makes a difference here. See the release notes of PostgreSQL.

You will however find plenty of information on the wiki. Sometimes it is not completely up to date because of so much going on on that front.

You can use third party solutions too, but they usually have a number of caveats and general problems. However it depends on what you do with your database. If you don't deal with writing your own functions, use extensions or have fancy transaction they will work just fine. If you do, the functionality of Postgres is a more safe strategy. If you are dealing with extensions, etc. you should really be ready to get dedicated support for these things.

However, it really depends on what you do. For everything standard it won't make too much trouble once the first setup is done.