After fresh install getting `psql: command not found`
According to the README included in the dmg file, postgres binaries are installed in /usr/local/pgsql/bin/. You should add these lines in your ~/.bashrc :

export PSQL_DIR=/usr/local/pgsql/bin/
export PATH="$PSQL_DIR:$PATH"


Update your environment with source ~/.bashrc or run a new shell and psql should be available.