Back in the days of Film Filters were king for taking a lot of images. There were great because you could have a piece of dark glass in front of your lens to take a longer shot; or a graduated filter for reducing the contrast between the sky and the scenery. A lot of people ditched filters when moving to digital photography as they could fix the photo in photoshop; and whilst some of the more trick cokin filters like (Cokin P056 Star 8 Square Filter) might not be appropriate anymore; having filters to deal with the augurs of daylight can be handy. The Coking Landscape Kit 1 comes with three filters.
The Warm FIlter is excellent for taking pictures of buildings; it darkens the sky a little darker and everything else a little less harsh.
There is a graduated clear to dark blue filter and this helps you get rid of grey skies as it changes the color of whatever you take that is covered by the blue tint section (this is also reduces the brightness slightly.
The final filter in the pack is a sunset filter; which amplifies the colors of sunset; again this is graduated only it goes from a similar color as the Warm filter to a dark orange.
The kit also comes with a filter holder; though you will need to buy a ring mount to attach it to your lenses. The benefit of the cokin system is you can buy one filter and use it on many lenses by buying relatively cheap adaptors for your lenses.