Scrum is all about daily collaboration and communication. You should do absolutely anything to make that easier for your team, as this will reap big profits down the line. That's why, if it's possible, co-locate your team members in the same room, aisle or space to make that collaboration more effective.
In many companies that's simply not possible due to building or distance barriers. That's okay. You can still be successful with scrum. You'll just have to work a bit harder to ensure sufficient collaboration takes place. Some things you can try are: Video conferencing, dedicated chat rooms and conferencing phones at all your locations. These can easily help your team stay in touch.
Now, let's talk a bit about the team composition. Your first priority must be to ensure that you have a dedicated team with you.
If your team members are multi-talking between your project and another one, they lose a lot of efficiency and that slows down your delivery.
Dedicating your core team to a single task, results in better focus, higher efficiency and faster delivery.
As per Scrum guidelines, the ideal team size is seven members, plus or minus two. I know this sounds specific, but research indicates these numbers maximize people's ability to create close relationships and collaborate most effectively.
Most of the time it is not possible to gather the team at one place for Scrum meetings and other work related issues. In such situations, Communication Channel plays vital role to collect team at one place. It may be a video conferencing or audio conferencing, just to share your current progress and discuss road blocks, if any.
If you take the time to work through these elements and help your team set the stage, success can come quickly for them. You will be astonished at how fast your team learn to work effectively once you have set them up for success.