There is no point (or space) for any explanation of Beowulf without being highly redundant. Rather I would like to say that this is by far the best Beowulf edition I have ever come across. The original Anglo-Saxon (Old English) runs along side the translated version of Modern English, page by page. The Old English however is in plain form (no long marks over certain vowels).
With a fantastic 32 page introduction (map and all), Explanatory Notes, Peoples and Genealogies Table of the Royal Houses (Danes, Geats and Swedes) and a glossary of proper names...this is a must for any one who is seriously interested in studying Beowulf at level of scholarship.
On the other hand, it is also a fantastic edition for the beginner, because of all of the explanation that the book provides. It does not however, simplify the text (like Cliffnotes for Beowulf).
Here is the first paragraph of the introduction:
Beowulf is to English what the Odyssey and the Iliad are to Greek language and literature. The oldest piece of vernacular literature of any substance not only in England but the whole of Europe, it breathes the true spirit of the northern Heroic Age. We cannot tell how it might have compared with similar epics composed at this time, since not others have survived. The various vicissitudes through which the medieval libraries passed meant that the preservation of the Beowulf-manuscript itself was a matter of mere chance. Because of changes in language, spelling and handwriting conventions, it would probably have ceased to be intelligible, or even legible, a mere two hundred years after it was written. But the poem was already several centuries old when this sole surviving copy was made, and close examination of the text suggests that it had a complex history of transmission, being copied several times in different parts of the country . Beowulf may have been very popular; certainly it was familiar enough for the name `Grendel's pit' or `pool' to have been used, presumably for fun, to describe boggy places in several parts of the country. And that the poem was highly regarded in literary circles is suggested by the fact that it seems to have been imitated in parts by certain writers of both poetry and prose.
I hope this is of some worth. This is a good book by Michael Swanton.