If you’re handing out flyers or pamphlets, there’s various pamphlets written by noted leftists. Orwell wrote a bunch of them, though I don’t suggest using Orwell for anything as he’s an anti-communist.

In my opinion, it’s always best to either write your own handouts, or use a handout written by someone in your community or political party. As that allows you to adjust the narrative to fit the material conditions of the local situation, and rally people using observable issues in communities that the handout recipients are already in. This is also nice if the community doesn’t speak English, people prefer to read important information in their native languages. This can also be helpful because it looks less like a communist screaming “read lenin” at passers-by, which is something anti-theorists seem to think is a problem on the left. (the absolute fools)

If you’re looking for texts that you can read that will help you explain to people why Marxism is important. The Communist Manifesto is always a go-for. ‘Foundations of Leninism’ by Stalin’s a pretty good one imo, but you should read it after ‘State and Revolution’ by Lenin. And I’ve noticed most popular communist theorists wrote short works while they agitated for revolution. Marxists.org is a great place to start looking, Lenin has a lot of shorties that you’ll find there. Also, don’t shy away from reading non-marxist texts, or texts that aren’t Marxist-Leninist, in my opinion, it’s vital that communist movements read as much theory as they can and constantly challenge their perspectives. It’s hard to do that if you only ever read ML theory. (crack open some ‘conquest of bread’ with the boys sometime, ‘libertarian’ and Anarchist theory’s got a lotta really good points. Also, it’s not a bad idea to read filth like ‘The Doctrine of Fascism’ by Mussolini, as it’ll give you a better understanding of Fascism and how people end up falling to such a vile ideology.)

I highly recommend reading Das Kapital at some point. It’s a fairly tough read, but definitely worth it to get a serious grounding in theory. Most serious leftist theory works relate to it one way or another making it fundamental material.

However, Wage Labour and Capital and Value, Price and Profit both encompass the central points of Das Kapital while being much more concise and easy to read.

I also highly recommend Lenin’s Imperialism, the Highest Stage of Capitalism and The State and Revolution. The first is a good intro to the mechanics of capitalism that lead to monopolies, capital concentration, colonization, and wars. The second discusses why reformism within the system is futile and the need for revolutionary change. Both are essential works in my opinion. Meanwhile, Lenin’s “Left-Wing” Communism: an Infantile Disorder reflects on how Bolsheviks built their movement and advice on power building for a serious working class party.

For more modern works I think that Michael Parenti’s Blackshirts and Reds and Inventing Reality are must reads.

I agree with those below, if you’re wanting to do a pamphlet on how to get involved, it should be from your party, telling them the importance of activism, of being in a party, and what organizing can achieve. That has to be tailored to the needs of your community and people’s local material concerns.

As far as a short marxist essay for beginners, IMO there’s no better than Lenin - The three sources and three component parts of marxism, and Engels - Principles of communism.