Does anyone have notes for important organizations?
Which you think is really good .
IAS4Sure publishes some good notes every year before Prelims. Have a look at them.
Spectrum's International Organizations book is really good if you starting from scratch.
You can view the contents here: https://spectrumbooksonline.in/product/international-organisations-conferences-and-treaties/
However, nothing can beat Internet. All UN organisations, Environmental Organisations, Treaties can be found in wikipedia. You can note down those CONTENTS and read in Internet.
NOTE: Also for prelims, UPSC focuses on Current affairs, so we can refer any good current affair magazines and IR Prelims Compilations of coaching institutes.
@Zigong [0_1550730963127_Important international organisation .pdf](Uploading 100%)
This might serve your purpose well for the major part!
Apart from that you can always supplement your knowledge from internet..focus on organisations that were in news in the past one year (for any reason)and read about their mission objectives, funding, membership, meetings related things from their website as in the past few years upsc is more tilted towards
asking some irrelevant facts about some low profile organisations so you can't afford to miss anything.
Ias4sure notes,ias parliament compilation and Internet research