Politics is the study of power, often through the study of government, institutions and decision-making. Below, you will find a list of things that you could use to learn more about Politics, or to improve a future application to university.
Books; Books come in a variety of sub-genres such as autobiographies of key leaders, books about political systems, books about particular topics or issues, but some recommended books include:
For the Record by David Cameron
A Journey by Tony Blair
Prisoners of Geography and Divided both by Tim Marshall
All Out War by Tim Shipman
How Democracy Ends and Politics by David Runciman
The Fifth Risk by Michael Lewis
A Year at the Circus by Jon Sopel
What Happened by Hilary Clinton
Divided We Fall by David French
Why Do We Still Have the Electoral College by Alexander Keyssar
Whilst these are general interest politics books, and you certainly don't need to be reading textbooks prior to university, one exception is An Introduction to Political Philosophy by Jonathan Wolff, which comes highly recommended by the Oxbridge universities in terms of pre-reading. Another recommendation is the Developments in British Politics series from MacMillan publishing who also publish Developments in Politics for other countries too.
Newspapers, Magazines and Political Websites; For any prospective Politics student you would need to keep up with current affairs and have a decent grasp of what is going on in the UK, US and major stories from overseas. The following resources would keep you up-to-date with events and provide analysis of them (some are behind paywalls but may offer free trials or limited free use); The Guardian; The Daily Telegraph; The Times; BBC; The Economist; The New Statesman; The Spectator; Holyrood Magazine (Scotland); Politico Europe; The New York Times (US); The Washington Post (US); Politico (US); The Hill (US); Conservative Home (Blog); Labour List (blog)
Politico have already been mentioned but they run a London Playbook, US Playbook, and other playbooks, which are essentially guides to what is going on currently, including lots of insider information and parliamentary gossip - they come highly recommended.
Podcasts; There are many good podcasts covering the latest political developments. As with all resources, you should learn to distinguish between opinion and analysis, and if something is clearly biased towards one side or outcome, then you should keep that in mind when using it. The BBC produce Brexitcast/Newscast (which they also show on their news channel); Talking Politics is the podcast of Professor David Runciman of Cambridge University (by all accounts the podcast that the politicians themselves listen to); Stories of Our Times by the Times newspaper covers a range of issues including politics; Comedian Matt Forde hosts a podcast called The Political Party in which he interviews a key political figure each week (in front of an audience when possible); Also recommended are Political Thinking from BBC Radio 4; UnHerd; and then from the US Pod Save America; NPR's Podcast; FiveThirtyEight (A well known political scientist in the US who successfully predicted an entire election, all 538 Electoral College Votes, hence the name); Can He Do That (Washington Post); CNN Political Briefing; Left, Right and Centre (three people from different political perspectives debating a current issue in US politics).
YouTube Channels; The major news companies and some political TV shows often have YouTube channels but some suggestions include; The Times; The Guardian; The Economist; The Spectator; The New York Times; The Washington Post and NPR. There are some good political discussions in the Oxford Union and Cambridge Union YouTube Channels in which they invite guest speakers to address the union and to answer questions, as does Intelligence Squared. A slightly off-beat suggestion would be the American current affairs comedy show, Last Week Tonight, which covers an in depth issue each week in an entertaining way, it is aimed at a 16+ audience due to some language used in the show.
Video; The Gresham College Lectures (Politics search) and Ted Talks (Politics) are good sources of information on political science and important trends, but you would be encouraged to keep up with current affairs by watching regular political shows and investigative journalism for example BBC Newsnight; BBC Question Time; BBC Panorama; and the Channel 4 News are all relevant in the UK. Documentaries are another excellent way to find out about politics, and some especially good ones on Netflix include; Mitt; Knock Down the House; Brexit (The Uncivil War); Whose Vote Counts (Explained); The Final Year.
Competitions; There are a great number of essay competitions that you can enter with politics related topics; The John Locke Institute essay competition; Duke's essay prize; New College of Humanities essay prize; The R.A Butler Politics Prize from Trinity College at Oxford University; The Robinson College Essay Prize from Cambridge University; The Libra Essay Prize; Minds Underground's Politics essay competition. You can also consider other types of competitions such as for debating, including the Donald Dewar Debating Competition (in Scotland); School Mace (England only) and then university organised competitions for school age debaters such as at University College London, St Andrew's University, Manchester University and Cambridge University.
Events or Activities; The John Smith Centre at Glasgow University advertise events on their website and their aim is promoting trust in politics and public service; you would be advised to participate in debating at your school, or to start a club if there isn't one; you could start a group who meet to discuss an issue from the news each week, or who read an article from a newspaper in advance and then meet to discuss it. If your school has a Model United Nations group you could participate in that, or start one, there are some good Model UN resources on the UN website.