At a glance
AだのBだの means "things like A and B" or "A, B, and so on". It lists a few examples, often with a complaining or critical tone.
[Noun / plain form] だの [Noun / plain form] だの（と）
弟はゲームだのテレビだので、全然勉強しない。 My little brother is always on games, TV and so on, and doesn't study at all.
How to form it
だの attaches directly to each item in the list:
| Attaches to | Form | Example |
|---|---|---|
| Noun | Noun + だの | 服だの本だの |
| Verb | Plain form + だの | 行くだの行かないだの |
| い-adjective | Plain form + だの | 暑いだの寒いだの |
| な-adjective | Stem + だの | 嫌だの面倒だの |
Register: mostly conversational. It is often followed by と言う to report what someone keeps saying.