I know next to nothing about metric sized tires. My former vehicle was a huge pickup with tire sizes in inches, which was so nice and easy
Anyway, here are some beginner basics for you that I just learned on my own... Someone else can help you with the "tire size" in metric and correct anything I'm wrong about.
Wheel Offset:
It's probably best to choose an offset between 40-45, but no lower or higher than that (correct me of I'm wrong guys). If you go lower than 40 you might have your wheels sticking out too far, and higher than 45 you could rub the brake calipers because it'll be inside too far. The lower the number, the farther out they stick. The higher, the farther inside towards the axle.
Wheel Width:
I believe the stock rims are 6.5 inches. So try to find something where you're not going to go too wide and have a problem with rubbing. I just bought rims that are 7 inches in width.
Wheel Height:
Your stock rims are 16 inches. If you want to keep your current tires, try to keep the width the same or close to it and go with a 16" rim in height. If you want, you can go up in rim size (17 and 18 inch rims are popular on elements too) but you'll have to buy a new tire. When the interior diameter of a tire goes up, the price also usually goes up. You can go down to 15" rims too if you like the beefier tire look, but be careful and do your research because some 15" rims will rub your brake caliper.
Bolt Pattern:
The Honda Element uses a "5x114.3" bolt pattern for the lugs. It's a fairly common pattern.
That's about all I can think of right now off the top of my head. Like I said, tire sizes will have to be someone else's forte!