Warning! Charging batteries without due care can cause the battery to swell and even explode. The information presented here is basic and should only be used as a rough guide in combination with other sources. When in doubt, set your charge rates low and increase only through successful experience.
Lead-acid battery technology has been around for more than 100 years. It is tried and true but the technology has reached a plateau. Because of the lead content these batteries are significantly heavier than other types. Depending on how they're constructed, they can either be used for high power output or long lasting applications. Much lower cost than other similar batteries but they have a much lower energy density by the afore mentioned weight, and also volume. Lead batteries also are less robust than alternatives so care must be taken to maintain them. Their low cost and high voltage per cell continue to make them popular, but as other chemistries come down in cost, lead batteries will continue to be phased out.
Very simple to charge. Just set your charger to stop charging at around 14 volts (check your batteries spec sheet for precise values). Be careful not to overcharge as these batteries produce explosive hydrogen gas when overcharged. Best practice is to use a constant trickle charge once the battery is full as these batteries suffer from 'sulphation' (the formation of sulphur crystals on their lead plates) if not fully charged, or not in regular use.
Bad for self-discharge, hense the recommendation to use a float/trickle charger when you battery is full and/or will be sitting unused for some time. If it does sulphate, high voltage charging pulses are supposed to disolve the sulphur crystals but there is limited information about this and I haven't tested it myself.