I have collected a list of useful resources for setting up and learning LaTeX here.

Some guides I have written:

• Natural Deduction Proofs in LaTeX: covers Fitch proofs, proof trees, truth trees, and Lemmon proofs.
• Quick TikZ for Modal Logicians: a gentle how-to for creating fancy diagrams in LaTeX. Also, for another great tutorial, check out Justin Khoo’s Causal Modeling Diagrams in TikZ.
• Modal Logic Symbols: a collection of some common (and some uncommon!) modal logic symbols. I’ve collected the commands for these symbols into a package file: modalops.sty. I also defined counterfactual biconditionals, which (as far as I know) are not in any other package.

Packages:

• Fitch Proofs: fitch (Kluwer, debugged), fitch (Selinger/Zach), or lplfitch.
• Proof Trees: bussproofs
• Truth Trees: qtree sort of works, but TikZ is more flexible.
• Diagrams: TikZ or XY-Pic
• Modal Logic Symbols: modalops.sty

Other guides:

• Logic: LaTeX for Logicians.
• Linguistics: LaTeX4Ling