You mean the two as separate practices or together?
Separately, Edred Thorsson's groundbreaking works on the runes are still the go-to I advise to everybody. There have been people who came later to the game that look down on him and wield the banner of 'historicity' to justify their claims, but I think the proof is in the pudding. Who has done the greatest works? I think historicity is thrown around a bit too much in the neopagan germanic/nordic fields and doing more magic and worrying less about certain things would yield more fruit. Just speaking of generalizations here. Archaeological evidence is spotty at best, as is shown for seidr itself. You'll find next to nothing historically except some descriptions, but no real how-to. Yet people are doing it now, reconstructing it, probably taking similar inspiration (shamanism is very, very similar world-wide) and adapting it. Same for the runes. You can't eat your cake and still have it. You can't accept modern seidr reconstructionism and poo-poo Thorsson. His works are far more 'historically valid'. (Not saying you specifically, NicholasUrfe, speaking in generalizations for this magical field).
Long story short, start with Thorsson's first three books and branch from there. His system is valid and inherently consistent, and you can go from there with others' books. I can't recommend any seidr books as I've only studied Harner's system of shamanism, whereas I worked through Thorsson's books/rites/system for years.
