Huge resources for reading are available online. Here are a selection.
The Calvin College Ethereal Library provides thousands of works from throughout church history to the present. It is invaluable.
Good Seed is an organisation focussing on the unity of progress from ‘Creation to Christ’. These are helpful books.
The Puritan Library also has a seemingly unending number of works from the Puritan era. Many of these works are available as ebooks, for kindle and other tablet readers.
Is a further Puritan site. Search by author or title. Some knowledge of what you may be looking for is needed.
Desiring God provide a series of significant works free in pdf format from this site.
The writings of C H Spurgeon are valuable for preachers. They are available here.