Early English Books Online (EEBO) contains digital facsimile page images of virtually every work printed in England, Ireland, Scotland, Wales and British North America and works in English printed elsewhere from 1473-1700.
Mount Holyoke College's Archives and Special Collections (ASC) includes a selection of titles from circa 1540 to circa 1680 on astronomy, mathematics, botany, medicine, and geography. If you'd like to see a Renaissance era book in person, you can do so in ASC! Note: the ASC book stacks are accessible by staff only, so it's best to contact ASC in advance if you'd like to look at a rare book. Call 413-538-3079 or email email@example.com.
Tips for reading early modern print
Spelling was not standardized, so expect variant spellings for words! (This is not a problem for searching in EEBO, however, because the database automatically searches spelling variations for you.)
Printers still used the long s (looks like an "f" missing all or part of the crossbar: ſ) as well as the s we're accustomed to today.
i and j are used interchangeably
u and v are used interchangeably
y is sometimes used instead of i
two v's are sometimes used to represent a w: vv
Overall, Early Modern English isn't that different from the English we speak today. Context (the words and sentences surrounding a word) will usually help you figure out what an unusually spelled word is.