You might've finished painting for the day but you should never rush the cleanup, otherwise your tools won't be any good for next time.
You're going to need lukewarm water, mild soap and plenty of patience. Begin by wiping off any excess paint using a cloth or soft tissue. Gently squeezing the bristles with your fingers or with a cloth will help to remove the paint from the brush, but don't pull on the bristles.
Next rinse the brush in lukewarm water if you've been using a water-based paint. Never use hot water as it can cause the bristles to fall out, then wipe on the cloth again to remove the last of the excess paint.
Wash carefully using a bit of mild soap (rather than dishwashing liquid) by dabbing the brush gently onto the piece of soap, then working up a lather in a small container or the palm of your hand if you're not using any toxic pigments or solvents. Rinse and repeat until there's no trace of any colour coming out, then rinse once more in clean, lukewarm water to remove any traces of soap. Never use a lot of pressure to force paint out of a brush, instead be patient and rinse it several times.
Shake off the water and use your fingers to gently shape the brush head into its correct shape. The next step is to wrap the bristles in a piece of tissue or toilet paper while the brush is still wet. When the paper dries it'll contract, pulling the bristles into shape.
Finally leave brush to dry at room temperature. Ensure it's not resting on its head as it will dry misshapen. Standing it on the back of the handle works well. For protection and longevity, store your brushes wrapped in newspaper or cloth.
Scrape the excess paint back into the can with a putty knife or similar, then rinse with warm water. Once you have removed most of the paint, add a little detergent and work into a lather. After this has been done, rinse the roller thoroughly and shake off the excess water. Next let the roller air dry, wrap it tightly in plastic wrap and close it firmly with a wire tie. Store the roller vertically because if it's stored on its side, that side can be flattened.
You'll need a bucket, old pan, paint thinner, newspapers and paper towels. The paint thinner is toxic, so good ventilation is required to avoid inhaling fumes. Put the roller in the pan and brushes in the bucket, then carefully cover them with paint thinner. Allow them to sit for several hours or overnight, and the oil-based paint will come off the brushes and rollers and settle on the bottom.
When that's done, bang the brushes and rollers gently side to side to remove excess paint thinner, then set the brushes and rollers on the newspaper and dab them with paper towels to remove any excess thinner. Finally, allow them to air dry. If all of the oil-based paint is not removed, you will have to repeat this process until it is.