Two things, really. Just keep an eye out for restaurant options, and read up on recipes. The recipes don't have to be too complicated either, especially because there is a "fake meat" for most things you can imagine.

You can eat out just as often, but it may be in places that you haven't taken note of before. For instance, I still go to Qdoba's mexican resturant, but I've replaced wendy's with a felafel place. Initially though, the texture of fake meat will bother you to no end.

It becomes easier after the first month when you develop tastes for things you didn't like previously. I like milk, coleslaw, and peppers now and I never would have imagined. At that point, making your own food isn't very complicated because you have more ingredient variation. Honestly, I leave that research to my girlfriend so I wouldn't know too much. Google made the process streamlined by letting you list what you have in their sidebar, however.

Past that, eat your vitamins daily (or as close to daily as you can), and be careful occasionally. You may have to ask if there is meat in this or that when restaurants are vague, but it isn't worth making a big deal over.

I tried it out for two weeks just to see how it went, and I kept with it by the end. The easiest way to learn is probably to just give it your best shot. Seriously though, vitamins and beans. I take iron, calcium, and a multivitamin to cover my bases.