There are tons of sources, but I will just give you two excellent ones here, both of which should keep you busy. For primary sources, the most well known is Bede's Ecclesiastical History of the English People, easily available in cheap editions. The best recent secondary source is Robin Fleming's Britain after Rome. It contains a wealth of information but is still very readable for the non-specialist. It will also have plenty of references to other primary and secondary sources.

FM Stenton's Anglo-Saxon England remains the great classic after a lifetime. The previous volume in the Oxford History series (itself still worth reading) was later split, with JNL Myres' new The English settlements covering the sub-Roman period. I've also high regard for PH Sawyer's From Roman Britain to Norman England, briefer but explicitly intended to supplement the older work (there's a more recent 2nd edition that I've yet to read, but I still find the 1st rewarding). I honestly can't think of anything later of similar standing and spanning the period.

Any special interests, period-wise or thematically?

u/pentad67 has given two books which are a brilliant starting point for newcomers to the period. I might add that another book which gives depth to the period is Gildas' On the Ruin of Britain. It gives the reader further context with which to place Bede, although it does focus on the native 'Romano-British' rather than their new neighbours.