Here are some resources I’ve come across that might be helpful for researchers, or people who are just interested in history (In no particular order, yet).

Ancient Olympics
Although it mostly looks like site for high-school students, if you actually click around, there’s actually heaps of primary source quotations throughout. Surprisingly useful.

The Diary of Samuel Pepys
For those who mightn’t know, Samuel Pepys was an Egnlish civil servant who kept a diary for about ten years in the mid 1600s. It’s an incredible glimpse into the everyday life of London at the time. While the whole thing is available, every day they post a new entry, corresponding to the one on the same date, about four hundred years ago.

Internet Archive
This is a bit of everything, archiving the web, TV shows, books, the works. For history students, there are a lot of old books saved here, surprisingly useful for primary or old secondary sources.

Old Maps Online
Pretty much as described. That said, it’s an incredible resource with a clever method of navigation. Search a city or country. Then browse and online map, and down the side appears a list of old maps relating to the region. Really cool.

Plutarch, Parallel Lives
One of the most famous histories of the ancient world. Plutarch wrote a biography of fifty famous Greeks and Romans.