Thousands of New Democrats are convening in Toronto this weekend, and tens of thousands more are expected to participate online, to pick Canada's next Leader of the Official Opposition.

The leadership race that was triggered by Jack Layton’s death in August has been long – seven months – and seven people are left standing.

The winning candidate will be elected in a way the NDP has never used before.

One member, one vote

More than 130,000 New Democrats are eligible to choose between Niki Ashton, Nathan Cullen, Paul Dewar, Thomas Mulcair, Peggy Nash, Martin Singh and Brian Topp. (Romeo Saganash and Robert Chisholm dropped out earlier in the competition.)

CBC live coverage

Follow all the developments from the NDP convention Friday and Saturday on CBCNews.ca, CBC News Network, CBC-TV and CBC Radio or via the CBC News App.

CBCNews.ca will have all-day coverage Friday and Saturday on our live blog, with livestreaming video of Friday's candidate speeches, Power & Politics with Evan Solomon and Saturday's CBC News special right up to the winner's acceptance speech. Join us online for live chats, photos, video clips and Q&As throughout the day or follow us on Twitter at @CBCPolitics

We'll kick things off with a live chat with Ian Capstick, Greg Weston and Kady O'Malley, Friday at 12 noon ET at CBCNews.ca.

This is the party’s first truly one-member, one-vote convention. Gone are the days when unions had special pull at NDP conventions. This time, their votes are not given greater weight; each vote by every member counts equally.

Events could also unfold in a very different fashion than the last time the NDP elected a leader. In 2003, Layton won on the first ballot, which meant the drama seen at other leadership conventions — with one camp crossing over to another or where multiple rounds of voting have ensued — didn’t play out.

It’s possible a winner could be declared after one round of voting on Saturday — but if not, then New Democrats could be in for a far more interesting day.

So, how do they vote?

Advance balloting

All registered party members were mailed voting packages that included a personal identification number that must be used to cast a ballot.

Advance voting began on March 1. Members can vote online or by mail using a preferential ballot where they rank their choices.

The mail-in ballots must be received by March 22 and advance online voting ends on Friday morning at 11 a.m. ET sharp.

All of the results from the advance voting are kept locked up, digitally, by the voting company that was hired for the convention.

Only a handful of people have access to those results.

The NDP will know how many people voted in advance and are expected to release that tally on Friday.

Round-by-round voting

The two-day convention opens with first-round voting opening Friday at 5:30 p.m. ET, after the candidates have presented their showcases and delivered their final pitches. Members who did not take part in the advance voting can cast a ballot in each round beginning on Friday night, with members voting for a single candidate each time.

There will be 175 voting terminals set up the convention centre in downtown Toronto, but members can also vote online from anywhere in the country. From the comfort of their home, or while they’re out for a walk enjoying their weekend, members can use their computer or smartphone to log on with their PIN and cast their votes throughout the convention.

On Saturday morning at 10 a.m. ET, the combined results from the advanced voting and the first round will be announced.

If one candidate receives more than 50 per cent of the vote, a winner will be declared — if not, a second ballot will be prepared.

The candidate with the lowest number of votes is eliminated and the remaining candidates will have 30 minutes to decide if they want to voluntarily drop off the ballot.

The rounds of voting will continue until one candidate passes the 50 per cent mark. There will be about 90 minutes between rounds for voters to cast their ballots.

Reaching voters outside the convention

The party will be keeping members who are not at the convention centre in the loop via email, letting them know who is on each ballot and when the rounds are set to begin.

Candidates in the meantime will be hard at work trying to get out the vote. They are setting up war rooms at the convention centre where their teams will be working the phones and their email lists to maintain and grow their support throughout the day.

Campaigns may also be pounding the pavement to make sure their supporters vote. Workers from Paul Dewar's campaign, for example, have been canvassing door-to-door in some communities to call on eligible voters. In some cases, volunteers have a tablet (mobile computer) in hand and help the supporter vote online right in front of them. This tactic was used during previous races in B.C., Manitoba and Ontario.

Members' first choice from the advanced ballot will be applied as long as that candidate is still on the ballot at the convention. When and if that person is dropped, their second choice and subsequent choices are counted.

When New Democrats will learn who their new leader is depends on how many rounds are required — it could all be over early Saturday, or it could stretch on all day.

The NDP is well aware, however, that Canadians' attention spans may wane the closer it gets to the time for the nation's other pastime — the puck drop for Saturday night's NHL games.