Yep, your calves will really feel it the first few times, until they get used to your new running style.
I'd say don't try to run on the ball of your foot, but land more on the mid-sole (just behind your ball, so your foot lands a little flatter but without the heel hitting the floor). Sounds odd I know and took me a while to get used to as I've always been a really heavy heel striker.
Try running up hill and you'll find that you do it pretty naturally, doesn't have to be too steep either, then you just need to remember how your foot is landing when you're on the the flat.
Before I got my VFF's I learnt this by reading up on Chi running and Prose running styles, plus watching a couple of good demos on youtube.
Both styles are pretty detailed, but you can get the basics quickly enough to make a big difference. I hadn't really run for over 5 years as my knees and ankles would hurt afterwards (I used to run 80+ miles/week in my late teens / 20's) due to old injuries and the stress of heel striking. But I started running on the mid-sole and literally overnight could run 3 to 5 miles without issue, apart from my calves punishing me for several days afterwards but in a good way