The Digital Preservation Coalition, of which DRI is a member, has published a series of 'Topical Notes' on Digital Preservation that outline the basics (and not so basics) of various aspects of digital preservation. They are an excellent, accessible read to familiarise yourself with the area.
This series of topical notes aims to address key issues of digital preservation for a non-specialist audience. Starting with"What is Digital Preservation?", the notes examine why digital preservation is important, while giving an overview of the steps needed to maintain access to digital information. Written specifically with record creators in mind, the notes also provide simple guidance on how they can ensure their digital records are preservation ready.