Beginning Spellbooks is a good product, if somewhat limited. Each book's spell list is thematically consistent with the background story provided, making it simultaneously a decent adventure seed and a reasonable piece of treasure for a low-level prepared arcane caster. The secondary effects, such as skill bonuses, make these books more than just a list of spells.

One of the more tedious parts of GMing, or creating experienced characters, is choosing spells for casters, so a resource like this is much appreciated. The problem is, choosing spells for 1st- and 2nd-level characters is easy, so the value of Beginning Spellbooks is much less than a collection of higher-level books. I wouldn't tell anybody to skip this part of the series, especially since it's a free download, but most people will get more use out of subsequent installments.