I need to create a user that has read access to all the schemas. Do they just need Select priviliges or is there more that needs to be done?
You can grant
SELECT ANY TABLE, however, that is seen by some as "excessive" privileges, and should be questioned.
On the plus side, Oracle 11 keeps key system views hidden even from that grant .. so it's not nearly as bad as it once was ;)
It would be best to build
ROLEs and grant the
SELECTs to the required tables to the
ROLEs ... then grant the
ROLE to your users as needed.
If you haven't yet, you should probably read over this guy: