I've always felt the lack of lower level monsters in any setting; but especially the old school with its stripped-down lists.
Dungeon referees who want something a little spicier than rats, skeletons and kobolds should therefore consider my new pdf supplement, available to download here absolutely gratis: Varlets and Vermin. It's a collection of monsters and related ideas for challenge levels 1 and 2, written for Swords & Wizardry but easily adaptable to other systems.
Please let me know what you think and if you find it useful. Thanks!