Early English Books Online, or EEBO for short, is among the most valuable resources for English scholarship. 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.
You can access Early English Books Online by searching for the title in the Online Journals & Databases.
Another option is to search EEBO-TCP, an interface that combines EEBO with the Text Creation Partnership (TCP). TCP creates standardized, accurate XML/SGML encoded electronic text editions of early print books.
Eighteenth Century Collections Online is a database containing facsimile and full text links to over 180,000 full-text digital items from the ESTC, published in the United Kingdom from approximately 1701 to 1800.
You can search ECCO's holdings using their basic or advanced search, or by browsing. Basic search, with keywords and phrases, is the best option for most searches.