Hi there,
What type of lighting do you have right now and what type of plants do you want to grow? Increasing light is a tricky deal when it comes to a planted tank because when you increase light you also increase the need for fertilizers and nutrients as well as Co2.(pressurized,
DIY, or excel)
Without a delicate balance between all three you will see poor plant growth and algae.
If this is your first time with plants I would recommend trying some low light plants as Ken mentioned and see what kind of success you have.
As far as light upgrades go Compact flourescent, T5HO are the best bets. 2-3 watts per gallon in larger tanks and more in smaller tanks. 6500K-10000K seem to look the best to my eyes but the plants as far as I can tell dont prefer one or the other.