Short Answer:
Toastmasters helps you with your public speaking and leadership skills. It really does help by giving people the opportunity to speak and have their opinions heard. For leadership, it gives people the chance to manage a local club, a group of clubs and even clubs across a district.

It also has a nice way of bringing together serious and like-minded individuals (because you have to pay), so there’s a good chance you’re meeting people who are just as interested in improving their public speaking as you are.

Long Answer:
Toastmasters manuals will give you an idea of what you can do to improve your speaking skills if you haven’t had an education on them before. With a meeting every month and lots of opportunities for people to participate, you can get a lot of speaking time in front of an audience.

No amount of public speaking theory or research is going to improve if you never speak in front of an audience, so a guarantee that you can be in front of an audience every month is very helpful.

Leadership opportunities can be hard to come by, especially if you’re in a workplace where there aren’t many leadership positions open. While you don’t get paid for taking up a leadership role, Toastmasters has a variety of leadership positions for a single local club, and there are leadership roles that go further than that, to the point where you can even manage the events that affect other clubs.

Meeting people at Toastmasters can also get you with serious and like-minded people who can be friendly rivals or encouraging support, both of which are great to have in life, let alone public speaking.

But if you’re walking into Toastmasters and expecting to be a master speaker in one meeting, that’s not going to happen. If you go to Toastmasters with the idea that you can be social but never participate, you won’t get many benefits.

Toastmasters can help you and it really is helpful. But it’s not for everyone, and it can’t make miracles overnight.