What Water and Peter have mentioned is correct -- and the Balmer-alpha line (aka H-alpha) is the main spectral line that ground-based solar observatories observe, if they're not using a broad filter.
... but you're not going to see a lot of prominences, as they're more commonly associated with the transition region ... and for that, you're going to need EUV, which is blocked by the earth's atmosphere.
And for flares ... I don't know if you'd want to be looking at the sun during a flare, but although there are flares in the visible spectrum (and in radio, but then they call 'em 'radio bursts') whenever people talk about 'M class' and 'X class' flares, they're talking about X-ray flares, which again, is going to be blocked by the atmosphere.
Now, if you wanted to look for events from space-based telescopes, there's a number of resources for space weather observing, where you can get data and images from NOAA and NASA satellites in 'Near Real Time':
(disclaimer : I'm involved with a couple of those projects, but I'm in IT, not a solar physicist, so I likely need to get one of my co-workers to verify what I said at the top, once this site is out of private beta)