I agree with everything previously posted, but I'd add one important piece of advice: Try before you buy.
I recommend that this is done before any kind of gun purchase or gear purchase wherever possible. If you can borrow or rent, do it before you start buying your kit and caboodle, and do it a lot. You will end up saving a lot of money through knowing exactly what you want to buy and exactly why you want to buy it before you do so, and that will save you from running through the hamster wheel of guns and gear.
You're going to be spending a lot of money if you commit to airsoft no matter what you do, so the only real way to save money on airsoft is to make really really smart purchases.
All too many times I have seen people purchase guns in particular only to find out that the gun they chose is just wrong for them. Too physically big, too physically small, personally uncomfortable ergonomics, limiting or cumbersome battery compatibility, etc etc. I've been through this myself. For many people, particularly newbies, this is very discouraging due to cost, frustration, and the fact that airsoft guns retain very little resale value in today's market.
In my opinion, bad (incorrect) guns, bad gear, and bad purchase planning together are the #1 cause of newbie dropouts. Don't get stuck in the money pit!
At the bare minimum you need
1. A good attitude
2. Good ($60+ dual lens recommended) full-sealing goggles
3. Face protection (mesh lower face mask recommended)
4. Decent boots with a high ankle that you've already broken in
5. Gloves (Mechanix gloves can be had for ~$10-$15 at Canadian Tire/ Princess auto/ Whatever)
6. Some kind of BDUs (this helps game organizers divide teams, they're tough, and you won't care about getting them dirty, sweaty, or torn)
That's $300-$400 right there and it's all stuff that sits right on your skin which you wouldn't want to share, as well as being essential for you to avoid serious injury. Once you have this stuff you can start showing up to games in your area, either at facilities which will rent you a gun, or games you find posted here. Many games will have a few people who may be willing to loan you a gun for a fee or collateral, which you can find by asking in a game's thread here on the forums or by going to games.
Just get yourself out there and don't rush into anything and you'll do fine.