http://gamasutra.com (Game Developer Magazine) is always my favorite place to just "browse" for misc articles. Usually, I'll go there looking for something specific, and stumble on a completely different and unrelated article that catches my interest.
"Oh hey, an article on pixel shaders, I always wondered how those worked."
or
"cell shading, now thats something that adds a stylish look- lets read that first".
Articles by Paul Steed (id Software modeller) really helped me out with Varium. Although the Gamasutra site may not give you specific info and how-tos, they pointed me to other resources, like Pauls Steeds now defunct "Thinking Outside the Box" articles at the equally defunct http://www.loonygames.com/content/archives/
http://www.flipcode.com is another interesting place to just "browse". Gamasutra has a better search engine built in, so its usually the first place I go.
Sorry this response is so broad, but without knowing specifically what you are looking for its kind of hard to just make a list of resources. (just general info of what Voxel is?) Its kind of like saying, "I am looking for a few good articles on poloygon-based maps"
