Learning Old English is language study, and like any language it has a natural progression: sounds and grammar first, then guided reading, then real texts. Jump straight to Beowulf in the original and you'll drown; work through the primers and readers in order and the poem becomes attainable. The sequence matters more here than in almost any other subject.
These books complement, not replace, structured study or a course if you can find one—but a disciplined self-learner can go a long way with them alone. Here's a path from first grammar to canonical poem.
First grammar
Start with a modern, gentle introduction: An introduction to Old English by Hogg lays out the essentials clearly, and Old English Grammar and Reader by Diamond pairs grammar with early practice passages. Work through these slowly, drilling the inflections—Old English is heavily inflected, and this early effort pays off everywhere later.
The classic primers and readers
Then the time-tested tools. Sweet's Anglo-Saxon primer and Sweet's Anglo-Saxon reader in prose and verse are the traditional gateway, dense but thorough. A guide to Old English by Mitchell and Robinson is the standard modern reference-and-reader, and The earliest English poems by Michael Alexander gives you accessible translated verse to keep motivation high while you build skill.
Toward the real texts and the wider language
Now aim at the summit. Beowulf; an introduction to the study of the poem by R. W. Chambers is the great scholarly companion, and Beowulf and the Fight at Finnsburgh is Klaeber's authoritative edition—the one serious students eventually use. For context, Old English and Its Closest Relatives by Robinson situates the language among its Germanic kin, and An Invitation to Old English and Anglo-Saxon England by Mitchell rounds out the culture behind the words.
Follow the full path and you can read the oldest English poetry in its own tongue.
