Cool
Is it Flourish Excel or Easy carbo? Both do the same job but are made by different manufacturers
I would imagine it's Seachem Flourish Excel, as I suspect it would be more readily available in LFS's. It's definately a good thing to use, providing a source of carbon for the plants to consume. You'll find everyone here either uses one of these, or injects CO2 gas into their tanks (or both in some cases!)
It might be worth looking at an all in one fertiliser in the first instance, till you get your head around things. Tropica Plant Nutrition+ (often refered to as TPN+) is a good one. Note the plus sign. Tropica do one called TPN, and one called TPN+. The first is a trace elements fert, while the second is an all in one with all nutrients needed.
Most people dose twice what tropica recommend on the bottle, but it'd be best to start at the stated doses, and up them over a few weeks and see if your plants grow differently
Most people also split the dose over several days, like Monday/Wednesday/Friday instead of dumping the whole lot in in one go. This is so there is always a supply of nutrients in the water
It's also worth reading up on Estimative Index (EI) in the ferts section of the forums! Much cheaper in the long run, but requires a little reading. It's not as difficult as it sounds though
Hope that helps!