Hi. the cokin filter system will provide a standard holder which will enable you to hold 3 slide in filters. They do a wide angle holder but that only holds 1 filter. The standard one will suit you in order to get you up and running. You will need an adaptor ring to screw into the end of your lens, and the filter holder slides onto the ring. Screw in filters are ok, but bear in mind that if you use a graduated filter it becomes a fuss arse method of lining the graduation line up to where you want it. Another problem you will have with screw in filters is, if you stack one on top of another, you will run the risk of vignetting. But slide in filters tend to be wider than the lens, so reduce (not 100%) any vignetting problems.
An advantage of screw in filters are they are more often made of glass, and that is less likely to scratch. Cokin filters are more likely to be made of resin. So if you do use Cokin, expect to be a little more careful with them. I personally prefer slide in filters, and have been using cokin for a few years. I will eventually upgrade to LEE, as they are the mutts nuts...... but naturally very expensive.