What exactly are all the leagues? What kind of skill do you need to play? Are there any leagues that play just for fun, etc. I'm not the best player in the world, but it would be great to play on a team.

ensl and ansl are afaik the only two leagues still operating (europe and american respectively), the nsp-l unfortunately came to a stop when there weren't enough active australian clans to support it If your a new player your best bet is to try join a less stronger team playing in a lower division. Theres generally not an awful lot of team recruiting and whatnot mid-season though. Competitive ns is fun, but you have to play seriously.

NS is no longer supported by CAL. Since you're in Canada, you're looking at ANSL (http://www.ansl.us) as the primary and probably the only choice. This is better anyway since ANSL is actually made by NS players for NS players, unlike CAL - although ANSL could use some more coverage.

I don't know what you mean by "leagues that play just for fun". I don't think such a thing exists since eventually you are still trying to win the game and not just goof around.

You don't need much skill to play competitively at the open level. Obviously if you want to compete on a significant level you'd need to be able to aim and move around well amongst many other things. However, if you want to compete, the most important trait and probably the downfall of almost all newcomers to the competitive scene is an incentive to stick around - there are hardly any scrims against players as terrible as you are (let alone the fact that scrims in themselves are just rare) and people just don't care anymore.

ANSL has two divisions - if you want to play at the veteran level, you should be at the point where you obliterate everybody in a pub besides other competitive players
The open division is much easier to get into - just join any team and start scrimming. Pretty much everybody can join, and everybody is expected to be bad. Just practice and you'll be less bad. A lot of the competitive players on IRC are willing to help out with advice, teaching some tricks, etc.

At least Europe still has some farmteams around here and then. A farmteam is generally a team of new players and a couple of more experienced players teaching and playing with them. You might want to join one if even one exists at American community.

The leagues have divisions for less skilled players too, but it may still be quite difficult to get the hang of it.

too many open teams in ansl are really made with vet people - i feel bad for the two or three teams that actually count as 'open' level and get bad matchups. not sure if we are at the point where we have one division but its worth talking about.

When does the season start/end?

usually 8-10 weeks. but for now ANSL has become ladder system that never stops and a good team are given a chance to beat the ladder champ every couple of weeks.

if you are really insterested in competitive ns and would like to play in active team you can always join some ensl team, ameriacans are always welcome(even assusies ).

we lag lots and suck at time difference tho