I have a separate posts about these two:
Näin is like this, so, and I saw:
- Tee näin. - Do like this.
- Ai se on näin kallis! - Oh it's so expensive! (Whatever you're talking about is kind of close to you.)
- Minä näin sinut eilen. - I saw you yesterday.
Noin is like that or so, and it is used what you can point at something.