Do Russians need a visa for Azerbaijan?

Russians don't need a visa for Azerbaijan - you can enter with a regular passport for up to 30 days. This applies to tourism and business trips. Your passport just needs to be valid, but you don't need to get any additional permits. It's pretty straightforward.

One thing - make sure before you go that you have current information, because the rules change sometimes. It's better to check the latest entry requirements on the official website of the Azerbaijan embassy or the Ministry of Foreign Affairs, so you're not relying on info from sketchy sources. If you're planning some kind of unusual entry (contract work, permanent residence), then you might need additional documents and a visa.