USA, Canada / Easiest way to get my mom a visa to visit the USA from Wroclaw? [11]

I haven't seen my mom in 2 years, she is in Wroclaw (where I was born). I have been living in the USA for about 10 years. Anyway, she works there full time, has an apartment, and I just want to fly her here for 2-3 weeks to visit. She has never been on an airplane, so that is going to be a challenge. But, the most important thing is getting her a visa with as little much grief as possible.

Has anyone else flown the mom's, dad's, brother's over for a visit and has some advice or a specific website, lawyer, that can help do this for low cost fee.

Thanks,

Aga