I'm assuming you mean to get your plants growing well and keep things like algae in check. It really depends on how you want to run your tank. Some people like the low tech version of things with no CO2 or fertilizers and set up their tanks accordingly and have great success. Other people like the high tech version of things and do pressurized CO2 and scrupulous fertilizer regimens and also have great success. They adjust their lighting and planting accordingly and go for it.
Most people starting out with a planted tank give tons of light, try DIY CO2, and don't do fertilizers. That's why new members here have Algae Grower as a title, presumably.