There isn't a right or wrong way to take a message, check the contents and assure the caller that you'll pass the message on. Use what feels natural to you.
Personally, when I take a message where I work, I wait until all the details have been given to me and then I say, "OK, so it's Bob from Smiths Limited, and you'd like to arrange a meeting to discuss some new products. That's great. I'll make sure he gets the message" or something very similar. If I've made any errors in my notes, then the caller is likely to stop me while I'm talking to correct them.
- OK, so it's Bob from...
- No, it's Bill!
- Ah, OK, sorry Bill! It's Bill from Smiths Limited ...
I will let someone else correct the contents of your original post as I'm afraid it's late here, my eyes are very tired and I'm going to sleep now!
- For Teachers