help with making appropriate indexes.

give this query: SELECT table_routing.id AS routeid, table_pricing.units AS price, table_routing.provider AS providerid, table_country.name AS countryname, table_country.id AS countrycode FROM table_pricing, table_routing, table_country WHERE table_country.id = table_routing.country AND table_routing.country = table_pricing.country AND table_routing.provider = table_pricing.provider AND table_country.enabled = 1 ORDER BY routeid what keys / indexes should I create on whatever tables to make this query efficient? I don't know if this query can be re-written even with JOINs and stuff. Please advise, If you've got an online doc. about that it will help too. Elias