Robbie is 10 weeks now and I got him a puppy collar and lead today. Put the collar on for 5 mins then back off again then kept repeating now he has had it on for 1/2 an hour. I have attached the lead to it but he started really crying so tried again but still no chance he cowers in the corner. I just want him used to it before we go out in a couple of weeks. Also is it better to leave the collar on all day while we are home and with him and just remove it before he goes into his crate at night. Any advice please.

Yes, I'd leave the collar on all the time when you're home with him. They usually dislike it to start with, but get used to it pretty quickly. I find clipping the lead on to it then feeding the pup starts to build good associations.

Thanks. I have kept the collar on and he seems to be coping with it now. Will try the lead on when giving him supper. When I put the lead on the pup my older dog is going bananas thinking he is getting hurt will try next time without him around either.

it sounds like u are trying to introduce the lead to him before he has got used to the collar. it can take some dogs a good week to get used to having their collar on fulltime. 
Once u are confident he is used to the collar u can introduce the lead, but as has been said put it on when u are going to feed him so he has good associations with it