If you are using Ubuntu 16.04 LTS we provide the latest stable releases of stellar-core and stellar-horizon in Debian binary package format.
You may choose to install these packages individually, this offers the greatest flexibility but will require manual creation of the relevant configuration files and the configuration of a PostgreSQL database.
Alternatively you may choose to install the stellar-quickstart package which configures a Testnet stellar-core and stellar-horizon both backed by a local PostgreSQL database.