With a 'paper slide' at Queen's Park, this election is officially on

The leaders have already been criss-crossing "every town in Ontario," to use the words of PC leader Doug Ford.

But today's the day the campaign really begins. Here's what you need to know on day one.

Headlines

• Green Party launches campaign in Toronto | The provincial Greens have never won a seat. Leader Mike Schreiner is hoping to do just that in Guelph. The party wants to capitalize on Green wins in B.C. and P.E.I.
• Ontario's election is Doug Ford's to lose | Our poll tracker shows Ford's PCs in a comfortable lead. But as the campaign begins, Ford will need to avoid saying things other parties — or even his own — can use against him.
• Will a 'PC blue wave' sweep over an orange Windsor-Essex? | As the NDP look to make gains, this is a key region for them to keep orange. Essex, with its NDP MPP, has voted federally for Conservatives in the past. There's no Liberal threat, at least not yet — the party still doesn't have a candidate in the riding.

The moment

You know it's campaign time when paper starts flying from the Queen's Park press gallery. The tradition, called a paper slide, marks the end of a parliamentary session — and the start of the campaign.

At first, politicians were the ones throwing the paper to signify frustration at all the bills that weren't passed. But at some point, the tradition became more celebratory and the media were the ones doing it.

More than a dozen giddy reporters showered MPPs in paper Tuesday as government was dissolved. They didn't have to worry about clean up though — that fell on Queen's Park's operation and maintenance team.

Riding to watch

Carleton, population 102,918, profile by Joanne Chianello

This brand-new riding in the south end of Ottawa has historically been Tory blue, and generally seen as a safe PC seat. But party in-fighting could hurt them. And Ottawa-area ridings are up for grabs, according to party insiders.

PC candidate Goldie Ghamari has been criticized by a prominent local MPP, who said in a leaked email last year that she didn't think Ghamari could win and if she did, she wouldn't be a good MPP. For her part, Ghamari, a lawyer, launched a complaint earlier this year that another local MPP physically intimidated her. The complaint was dismissed.

• Here's why Guelph is a riding to watch

Alternately, Liberal candidate Theresa Qadri is a real-estate agent and community volunteer with roots in the area. Her husband is the local city councillor. And just last week, the Liberals promised to spend $50 million to extend light rail into the riding, which is currently poorly served by rapid transit.

Vote Compass

Today also marks the launch of Vote Compass, our tool designed by political scientists to find out how your views line up with the four major parties.

After answering a series of questions on everything from transit to Indigenous issues, the tool shows you what party your views are most closely aligned with.

You can try it out here. We hosted a lunchtime live blog with one of the tool's creators Wednesday, where he revealed users have even used the tool "to screen potential dates."

Where the leaders are

• Ford: Announcement in Etobicoke (9:30 a.m.), cafe stop in Carp (3:15 p.m.), rally in Renfrew (6:30 p.m.)
• Horwath: Healthcare event in Toronto (9:30 a.m.), coffee shop stop in Toronto's Davenport riding (2:30 p.m.)
• Schreiner: Campaign launch in Toronto (9 a.m.), event in Hamilton (12:30 p.m.), event in Kitchener (3:30 p.m.), event in Guelph (6:30 p.m.)
• Wynne: Announcement in Etobicoke (8:30 a.m.), visit to Yee Hong Centre in Scarborough (11:30 a.m.), rally in Ottawa (6:00 p.m.)

For more Ontario election coverage:

• Ontario Poll Tracker | The latest developments
• Vote Compass | See how your views compare with the parties' platforms
• Complete election coverage | Links to all our stories
• Help CBC track political ads on Facebook | Learn how here