This is my follow-up to my Step 1 post of a few days ago, in an attempt to spread word of the non-converged alternatives to Official D&D (including Pathfinder for this purpose). These are the most popular clones.
- OSRIC is the clone of AD&D 1st Edition I mentioned. Even if you use the official rulebooks, having this on hand is useful as it clarifies the language.
- Labyrinth Lord is the clone of the Moldvay-Cook version of Basic D&D (the one before the famous Basic D&D set of the 80s that broke D&D into the mainstream). Two supplements allow LL to clone AD&D and Original D&D.
- Dark Dungeons is the clone of the more famous Mentzer version of Basic D&D (the "BECMI" version, collected as the Rules Cyclopedia). Print versions can be had (in the US) at Lulu, and there are multiple options. (Search by author for full list.)
- Swords & Wizardry clones Original D&D.
- Basic Fantasy is a very cheap variation on Basic D&D. It's also the only one available at Amazon if you want a print copy, along with a great array of supplements, and all are $5(US) or less. PDF is free.
From there you'll be more than able to make or find whatever else you want.