From the photo it doesn't look like Buster needs/is ready for a full trim yet. How old is he ? Misty's puppy coat didn't give until she was about 7 months old, so prior to that I just tidied up her paws, inside of ears and her tail end using scissors and also started to handstrip the head a little to get her used to it. Even if you plan to take Buster to be groomed professionally it's worth learning how to do these basic bits so that you can keep him as tidy as possible between trims - I find the paws need trimming about every week or two otherwise they drip water everywhere and collect all kinds of debris.
Have a look at the "What Is Hand Stripping ?" thread that is pinned at the top of this section - not all professional groomers will handstrip as clipping is much easier and quicker for them to do but it gives a much harsher finish, whereas stripping leaves a nice silky natural look on an adult Cocker. A compromise is to use a stripping tool called a Coat King - you can get a nice enough finish for a pet Cocker with one of these. I'd try and avoid having Buster clipped as it can ruin the coat for good.
If you fancy learning to trim Buster yourself then all the information on what to do and what tools to buy is in this section - it takes a bit of time and practice but can be quite fun to do and save you a lot of money in the long run.
