Fordham University has a good general Ancient History Sourcebook
Classical scholarship well indexed by L'année philologique, vols. since 1969 are available frorm CC computers online: you can choose to navigate in English by picking a flag at the top. This lets you, after a little trial and error, find out what was published in the 1990s on Herodotus, or what Carolyn Dewald wrote besides the intro. and notes to our Herodotus, etc.
Classical scholars' electronic consortium projects are collected at the Stoa, where you'll find a number of really interesting resources:
Classical Greek and (increasingly) Latin texts and English translations, along with commentary, encyclopedia, a narrative history, dictionaries, grammar helps, images of paintings, sculpture and architecture, maps and more are available on the huge and important Perseus site, where you should try to use the new 4.0 implementation.
Maria Pantelia of the TLG project has a somewhat up-to-date page of Electronic Resources for Classicists.
Persian sources are collected by the dean of Ancient Persian studies, Pierre Briant at the Collège de France, in his over-busy Achemenet site. Also at the a good Zoroastrian Avesta site and at the Oriental Institute of the University of Chicago. Particular texts: