Unfortunately EAs rarely think about helping during war, because it's difficult to find cost-effective interventions in a war zone (I think the best time to help was before the invasion started.) The Ukraine situation is especially sad to me, because European countries (or the US) did not offer to directly defend Ukraine before (or after) Putin made his veiled nuclear threat. But I encourage EAs to think about this today, offer ideas, and share relevant news stories and names of trustworthy blog posts and analysis (with summaries).

• Related EA forum question (Update: also here; large donors see here)
• Update: Bellingcat (on Twitter) analyzes footage in Ukraine (and elsewhere) to debunk, verify, and geolocate (donations accepted)
• Tips for helping Ukraine from Ukraine Crisis Media Center.
• Expect Russia to cut off internet access. Officials are asking for Starlink. (Update: first shipment of terminals delivered Feb. 28. Words of warning—even Musk says using Starlink is dangerous.)
• Aide to Polish PM: "Everyone seeking help in Poland will be able to receive it."
• February 2022 Survey: "49% of all adult Ukrainians...say they will volunteer to fight or serve in Ukraine’s armed forces if a new Russian offensive happens. 10% are undecided, only 35% said they would not themselves volunteer"
• Analysis from a military historian (who doesn't believe the conflict was avoidable). Update: a month ago, Binkov's Battlegrounds predicted what would happen if Russia invades fairly accurately so far, and it offers other informative military videos. And Scott Alexander points to Clay Graubard as the one who made the best prediction of invasion, while Clay and friends offer further depressing predictions along with a summary of Metaculus (etc.) predictions: Zelensky will be ousted/killed/captured, Putin probably won't, (very roughly) 50,000 people will be killed, and Kyiv is more likely than not to fall this month likely to fall within a few months.... I'm finding it informative to follow @WarSignals, superforecasters, and people they follow, on Twitter.
• Thread about how non-soldiers can help defend their city.
• Organizations are manpower-limited so I'm not sure how useful it is to send money to the same orgs to which everyone else is sending money, considering that Ukraine needs help right now today. That said, the war could be very long and it's worth considering how to provide long-term help. Here are some orgs found by quick Googling:
  • "Vostok SOS, based in Ukraine, partners with German-Swiss NGO Liberico to provide immediate evacuation support to Ukrainians attempting to flee their homes."
  • "Save the Children: an international NGO delivering emergency aid to Ukrainian families"
  • "Phoenix Wings: a charitable foundation that supplies the Ukrainian army with medical treatment and defensive equipment such as vests and helmets"
  • "Kyiv Independent: a Ukraine-based, English-language independent news media outlet"
  • Norwegian Refugee Council plays some kind of role
  • Doctors Without Borders operates in Ukraine & Donbas (update)
  • Razom is a Ukrainian-American human rights organization with its own list of recommendations, as well as accepting donations itself

Hi, Valmothy! I'm Nina, and last year I started an EA community in Kyiv. Have been organizing a lot of stuff and asking myself the same kind of questions for the last three days, let's combine our efforts! You can find me on EAhub, there are links to different social media: https://eahub.org/profile/nina-antonyuk/. 
Please write to me! Be safe!

Hey Valmothy. I don't know the answer to your question but if you or your friends or family are in Ukraine and need help getting out feel free to signal me on +64212129849. I can put you in touch with some folks who might be able to help (info, support if you cross into Poland, $).

Great question! I am upvoting!  Also just want to say that I am very sorry that Ukraine is left alone and as a Polish citizen (now living in London) I will try to help in whatever capacity I can. My friends are already helping in Poland with transport and housing for refugees. We stand with Ukraine! We are very sorry that the World is just standing and watching this, we hope there will be more sanctions and weapons delivered soon. 

And yeah I join your problem - also not sure what are the best opportunities to donate to. So far I supported Polish Humanitarian Action, because they already were helping in Ukraine, so they know organizations on the ground, and they are respected and trustworthy (they helped in many war zones since 1992, including Syria, Iraq, Afghanistan or Chechnya). However, I would like to donate to a Ukrainian organization but it's hard for me to understand where is the best place to donate.

I will however support Ukrainian refugees directly. Either with money, transport,  or housing in London if needed. 

All the best to you! I hope your friends and family are safe! 

I don't know much but I found this discussion a good starting point: https://forum.effectivealtruism.org/posts/qkhoBJRNQT4EFWos7/are-there-effective-ways-to-help-ukrainians-right-now

I've submitted a very rough draft of how we could profile charities (and perhaps other organizations) to get a feel how they contribute:

https://forum.effectivealtruism.org/posts/gacpE79RKke2foG9K/rough-attempt-to-profile-charities-which-support-ukrainian

I appreciate your feedback, I'd be happy to get this ball rolling.

I registered on this site to search for like-minded and not indifferent people. Unfortunately, my lifestyle does not allow me to use this network for its intended purpose at the moment, but I chose this path myself. My son and I provide assistance every day to residents of Ukraine who do not have the opportunity to purchase provisions, we provide only those who cannot provide themselves with food, mostly small settlements in the vicinity of the line of contact of the armed forces . Funds created by many kind people and the state provide tremendous support , but unfortunately the time that bureaucratic regulatory tools take is long , and people need help every day . My son suggested contacting the not indifferent residents of developed democratic countries through social networks and forums with a request for donations in bitcoin, arguing that this is currently the fastest way to transfer money in the world. I don't fully understand what it is, but I found confirmation on the Internet that after receiving funds in 20 minutes we have the opportunity to purchase what many residents need right now. Basically, these are old people who have nothing left but to wait humbly and eat what they will be brought. Fortunately, we have people who provide daily assistance in the field in which there is an opportunity. They don't charge us for repairing our small truck , they help us buy fuel . In some places, they give us food for free , but unfortunately, all these kind people have fewer opportunities to help than those who need help every day. We do not condemn people who refuse to help, because we are all in a very difficult situation , we do not evaluate someone's contribution to a greater or lesser extent , any contribution is something that can give someone the opportunity not to go hungry today. We have no right to force anyone . 
If you have the opportunity and desire to do a good deed, we will be glad to receive any donations. Our wallet bc1qrgzcm6exx0vchyj089jzspa6vyjcs65zzxskd0xe04qa8h83lxks7ldh38