Best read performance when every query is known, and the data doesn't change
Off the top of my head, here are a few things to do, in no particular order.


VACUUM FREEZE
ANALYZE
Add the indexes that you think are going to help.
Execute as many queries as you can.
Look at pg_stat_user_indexes to see which queries are being used.
Look at the EXPLAIN ANALYZE plan for each query.
Review https://wiki.postgresql.org/wiki/Slow_Query_Questions
Review https://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server
Post follow-ups with server specs and questions to SO or the Postgresql mailing lists (most of the core developers answer questions in the pg lists).


It will likely be an iterative process, so don't expect to get it right in the first go.