How to get started with procedural maps?

I'm talking about random map generation like in AoE2 that determines where tiles/resources/etc are. I'm not new to making tile graphics but I'm just dipping my toes into actual procedural maps so I need some place to get started.

 

Google is your friend.

Academic papers:

Procedural Map Generation for a RTS Game, Lara Cabrera, et al.

PSMAGE: Balanced Map Generation for StarCraft, Uriarte & Ontanon.

Tutorial:

Complete Guide to Procedural Level Generation in Unity, GameDev Academy

These are just links for RTS-style map generation since you mentioend AoE2. There are loads of papers and tutorials for dungeon and platformer map generation, but they're probably not as relevant.