Generally lead acid cells fall into two categories. They can be designed to tolerate deep discharge very well, or they tolerate overcharging very well. Generally if they do one well, they are pretty intolerant of the other. I.E. those designed for deep cycle use don't tolerate overcharging very well, and those that tolerate overcharging very well (automotive), don't tolerate being deep discharged very well.
Lead acid cells are best charged with a constant voltage charger that is temperature compensated, and if properly vented, most can actually be charged at high rates (~C).
However low rate chargers are widely available, and low cost, typically an automotive type storage battery will tolerate charging at about 2 amps almost indefinitely. So long term charge rates in the C/40 to C/80 range are generally regarded as safe.
Overcharging does result in the electrolysis of water, so most automotive batteries are designed for to be able to add water to the cells to replace that which is lost. It takes a lot of overcharging to remove significant amounts of water (check out how many amp seconds it takes to move 1 Mole of electrons). It also tends to slowly convert the lead plates to lead sulfate, reducing storge capacity.
As others have pointed out, these cells aren't the greatest in terms of energy density, they are quite robust relative to most rechargeable cells however, and will tolerate very high discharge rates.
They are. are relative inexpensive for the capacity they provide. Just remember that the electrolyte is sulfuric acid, so handle with care and dispose of properly.
