How much energy does a wind mill generate daily?

I don't want to avoid the question, but it is something like asking how big a lake is. Some are tiny and some enormous. Similarly, you may be asking about a small windmill on an farm in Lancaster, PA producing kilowatts or a large "wind farm" that connects to the east coast power grid and produces tens or hundreds of megawatts. A wind farm connecting the the Eastern Interconnection will tend to peak in the tens to low hundreds of MW.

Output will vary by design, amount of wind on a given day and by location. Typically windmills are installed in the "wind farms." The farms are then connected to the Eastern Interconnection.Take a look at PJM's Generation Queues. Filter by fuel type = wind. There are several examples in the Z2 queue. Click on the green circle under FEAS (for feasibility study report). You will find the plant output in MVA under General. If you are not overwhelmed and want more details, click on the green circle under IMP (for System Impact Study Report). You can find similar information for the Midwest at misoenergy.com. Again, search the site for generation queue. Other US energy markets you might want to check are nyiso.com, iso-ne.com, caiso.com.

Search the internet for "wind map United States" to see where it makes sense geographically to install wind resources. Also, be aware that too much wind is as bad as too little wind.

You can find a wealth of information in the PJM Renewable Integration Study (PRIS). See the
February 25
PRIS Task 1 Wind and Solar Power Profiles - Final Report
, 2015.
The PJM Renewable dashboard shows a summary of Wind Power in the region.
Stating at the biggest, the world's largest wind turbine is now the Enercon E-126. This turbine has a rotor diameter of 126 meters (413 feet). This new turbine is rated at 6 megawatts, but will be able to produce produce 7+ megawatts (or 20 million kilowatt hours per year).
The smallest turbines which produce fractional outputs are uses to activate wate pumps for cattle in many areas.