Filter media is what actually goes into the filter. It is fits into 3 categories. Biological which is normally a sponge or other items Bactria can live on/in. Chemical is normally carbon and clean chemicals out of the water column. Mechanical removes small to large partical from the water column.
As far as test kits you want something like this
http://www.apifishcare.com/Products/...x?ProductID=67. Liquid test kits are more accurate the strip test kits but Any you can afford are better then none.