Slow draining

The drain where the water from the kitchen sink runs (also the bathroom sink and bath) overflows every time I run the tap or empty the sink. The water does go down eventually but it takes quite some time. I am guessing that the drain is blocked - would it be simple for me to unblock it myself or should I get a plumber in?

Many thanks for any advice.

If you have a Drains R Us in your area, give them a ring.

I had the same problem and they put a drain snake down and cleared it for less than £40