This system is used in Germany. First, representatives are elected in an FPTP fashion. The rest of the seats are then given to at-large members in proportion to the percentage of the vote that their party received. It is unlikely that this will be concentrated in any one riding, and so the Greens will probably not elect an individual representative. This is by far the most popular form of proportional representation.
All parties provide lists of candidates which are displayed on the ballot.
The voter votes for a party rather than an individual candidate. Some party list systems allow the voter to also give his preferences as to individual candidates, but those candidates must be in the same party that he is voting for. The seats up for grabs are then allotted to the different parties according to the percentage of the vote they received. It is a very straight forward system and ensures proportional representation. This is a system that is presently in use in Australia, Ireland and France.