It obviously depends on the type of plant you plan on growing, but below is a pretty good place to start.
Generally, plants grown in pots require perfect drainage. Garden soil is not ideal because it is often too heavy (drains poorly) or may not hold nutrients in the mixture very well. Pots/Planters tend to get watered frequently which leaches nutrients and you therefore need components that "hold on to" the fertilizer nutrients.
Your choice of material depends on availability and there are substitutions you can make based on your preferences (e.g. coir instead of peat, if you happen to agree with statements that peat leads to depeletion of bogs and that coir being a recycled waste product is preferred from an environmental point of view, etc).
However, will not go into the "ethical" discussion here but try to list my suggestions based on "generic" considerations.
You need a planting mix which holds moisture, and nutrients, which drains well and which allow roots to expand well.
A good mix would be 30% peatmoss sphangum, 40% perlite or woodchips, and 30% compost. You can also make this 33%,33%,33% if you like. The perlite (or woodchips) provide for good drainage. The compost is generally heavy and so is peatmoss but combined they form a very nice consistency which holds fertilizer nutrients well.
Some people add vermiculite and that is ok, but If you use compost in addition to the peat, it is really not necerssary.
If you add woodchips, then make sure you use a slightly higher nitrogen fertilizer to offset the nitrogen reduction as result of decomposing wood (e.g. say 20-10-10 instead of 10-10-10).