With one of those little indoor antennas? Not much.
Put a decent directional antenna outside on a pole, your roof or a small tower, and you'll see a lot of channels! Twenty or more.
Most of the broadcast stations also have digital subchannels. For instance, WOOD-TV at 8.1 also has WXSP (8.2) and weather radar (8.3). WZZM-TV (13.1) has a weather station at 13.2. WXMI-TV (Fox 17) at 17.1 has two neat subchannels (17.2 and 17.3) that run round-the-clock movies and old TV shows.
Digital broadcast reception is different from the old analog broadcasts. It's either coming in or your screen is blue. No more ghosts and fuzzy viewing, but it can be frustrating at times when the signal drops.
I haven't found that the weather has much effect on the signal, which is coming at your antenna by line of sight.
I've found a signal has to be at least 20 percent to be reliable. From where I live in Grand Haven Township, I point my outdoor antenna (about 32 feet in the air) at Kalamazoo. WWMT-TV (3.1) comes in at 40-50 percent, while the Grand Rapids stations still come in strong enough (30-70 percent). WGVU-TV (35) and WTLJ-TV (54), both with towers in the Allendale area, are upper 80s to near 100 percent.
There's free help on the web. Go to antennaweb.org to find the exact channels you can get, how strong their signal will be for your location and where to point your antenna (if it's directional) to pull them in. Click the "click here to start button," type in your location information and click "submit."
The site also has helpful information for buying an antenna (an outdoor directional antenna as high up as you can get it works best).