The list below is far from comprehensive and in no particular order. If you believe in Monero, there are ways you can help regardless of your time limitations or level or technical expertise.

1. Support Monero community funding proposals and donate Monero to privacy focused projects:
https://forum.getmonero.org/8/funding-required
https://subgraph.com/sgos/documentation/monero/
https://geti2p.net/en/get-involved/donate

2. Vote for Monero:
https://tutanota.uservoice.com/forums/237921-general/suggestions/9968298-accept-monero-xmr-for-donations
https://protonmail.uservoice.com/forums/284483-feedback/suggestions/14308680-accept-monero-payments-for-protonmail-plus-and-vis

3. Define Monero terms:
https://getmonero.org/knowledge-base/moneropedia/
https://monero.stackexchange.com/questions/1178/how-can-i-edit-a-moneropedia-definition-or-add-a-new-one
http://meta.monero.stackexchange.com/questions/128/improving-tag-wikis-and-usage-guidance

4. Help translate this and other important Monero content:
https://getmonero.org/knowledge-base/user-guides/
https://getmonero.org/knowledge-base/developer-guides/

5. Add your business to the merchant and services directory:
https://getmonero.org/getting-started/merchants
http://monero.stackexchange.com/questions/1049/how-can-i-add-my-business-to-the-merchant-list-on-the-monero-website

6. Get active on Monero Stack Exchange, help keep our activity levels high and share interesting questions with others:
https://monero.stackexchange.com/
http://area51.stackexchange.com/proposals/98617/monero

7. Every time you spend Bitcoin, use the services below then email the merchant to let them know that you would prefer if they accepted Monero directly. Let you favorite business know that Monero users are loyal to those that value privacy.
https://xmr.to/
https://shapeshift.io/

8. Mine Monero and run one or more full nodes:
https://getmonero.org/getting-started/running
https://www.reddit.com/r/MoneroMining/

9. Run an I2P node and help test Kovri when appropriate:
https://geti2p.net/en/about/intro
https://github.com/monero-project/kovri
http://monero.stackexchange.com/questions/2617/i2p-kovri-fundamentals-in-monero

10. Join the Trello community board:
https://trello.com/b/5R2ly4mV/monero-community-contributions

11. Support merchants and services that have made the wise decision to accept Monero:
https://getmonero.org/getting-started/merchants

12. Create Monero related audio and video and share existing content on social media.

13. Register an account and start becoming active on https://forum.getmonero.org

14. Start using https://bitsquare.io/ and help increase trading liquidity for Monero on the P2P decentralized exchange.

15. Compile from source, test new features and report issues on GitHub:
https://github.com/monero-project/monero/issues
https://github.com/monero-project/monero-core/issues


If you have more ideas for community tasks that can be added to the list please share!