there are cheaper ways to go about it, but I used Foratis and cannot speak higher of their service and product. My partner also formed her own UG but used firma.de, hired a certified but inexpensive official translator, and it took nearly four months from start to finish.

Note that Foratis does not do the VAT registration for you, like some other shelf corporation providers. I didn't realize this and it became a minor pain. Whatever you do, budget for a competent Steuerberater. DIY is nearly impossible unless you have strong German skills, and even my native business owner friends don't DIY when it comes to Finanzamt dealings :)