This can make all the difference in the world! I just finally adjusted my Revo Winch to where I want it. Enjoy the info!
Setting the brakes is very simple on the low profile styles of Shimano and Ambassadeur reels. Just remove the cover on the left side and pull out one of the 6 plastic weights to tighten the brakes or push it in to loosen the brakes. Revos have a knob on the right side that are usually finger tight (but could require a screwdriver to loosen). It must be loosened before the left plate can be removed. The round style Shimano reels (Corsair & Calcutta) are a little more complex. The brakes are in the same place and they are basically identical, but you must remove the spool from the right side of the reel to get to the brakes.
Many reels have brake control knobs on the left side of them (usually instead of centrifugal brakes). In most cases, you can tweak them by following the same procedures as the brakes. They will usually have +- or more/less written on them. "+" or "more" usually means more brakes - not more distance. So, don't get that confused. Also, don't get the brake confused with the friction adjustment.
Here is the link I found to the info above that was pretty simple and descriptive:
http://www.bassfishing.org/BassFishingTips-HowToTweakABaitcastingReel.htm