I check novelupdates.com basically every day for 'Overlord.' The fan translation scene moves fast, sometimes faster than the official releases, and that site is the hub. You have to sort by 'Series' and then check the forum thread. The translation group, Hitori-sama's project, usually posts updates there, and the community is pretty good about flagging when a new chapter drops.
That said, the last volume was a while ago, so the 'latest' updates right now are kinda sparse. The discussion on the forums is more about speculation and memes than new chapters. I've seen some aggregator sites pop up with machine-translated stuff, but the quality is a real gamble—names get mangled, and the nuance of Ainz's internal monologue just vanishes. I'd stick with the fan translation, even if you have to wait.
Sometimes the official Yen Press version is actually ahead. I got their digital copy of volume 14 the day it released. So if you're really impatient and don't mind spending, the Kobo or BookWalker storefronts are solid. But for free, consistent tracking, Novel Updates is the place. Just be prepared for forum posts that are like, 'Any news?' repeated every three days.