This depends a lot on your intentions,
You can set out some rough guidelines (I need a bunch of islands and a big desert on the same continent as some quality farmland) and then work from there, figuring out what you need to get it. But if you get too detailed you will end up having to change things. The other approach is just to create a world and write the story to fit it, computer generation is your friend there, since it will work out everything for you.
Assuming an earth like planet, two things decide climate continental position and average temprature, everything else gets derived from those two things. Continental position and planetary air cells (which don't vary much) decide most of your climate with average temprature deciding more overall trends. I will mention each one briefly because each could be a question in and of itself, which not be a bad series.
Air cells form fairly straight forward patterns, and control prevalent wind directions. They can be simplified into rising air is warmer and wet and flavors forests and descending air is cooler and dry, and favor deserts. Large biomes generally will not cross these cells, the exception is if they are very narrow and bordered on one side by mountains and coastline on the other.
Continents in how they are moving tell you where your mountains and volcanoes are, how easy it is for ice sheets to form, and where your rivers are. the same continent at a different latitude can have a very different climate due to which air cells it is interacting with but there are some general trends. The leeward side of mountain range is drier and the windward side is wetter, and the bigger(taller) the range the more extreme this is, this called rain shadow. Rivers mostly flow from mountains to the coast, merging into bigger and bigger rivers the farther they go. One of the easy give aways of a fantasy map is rivers that make no sense. If you have continents close to or over the pole it is very easy for ice sheets to form. Continents also of course shape your oceans and ocean circulation can have a lesser effect on climate as well, for instance the flow of water from pole to equator in the atlantic keeps the east coast of the US wet and warm.
Of course continents themselves have rules, continents tend to have coastlines/bordered they are a collection of 120 degree angles connected by rough more or less straight lines, this is caused by how rock breaks under pressure. The exception is subduction arcs which form arc shaped islands or island chains (see alaska or japan) Another easy give away of a fantasy map is continents with long straight coastlines or many smooth curves.