I would say that you should stick to higher reps (10-15ish) for a while until your body gets used to the new training you're giving it.
Maybe stick with that rep range for the first 4-6 months or so, changing up your routine a little, every 6 weeks or so.
I keep saying "or so" because everyone's different, but being a begginer you should give your body plenty of time to adapt.
Remember, this should be a life-long thing you're doing. Consistancy pays off. Make it as routine as brushing your teeth (or even more so for some).
Read a LOT of articles on this site, as this is by far the best free site I've ever been to for QUALITY advice.
Here's probably the best place to start:
Read through it all, then read it again. Click on the links vroom provides and read them. It's definitley worth the time it takes to get through them all! Even if it takes you a while.
Just remember to keep doing something as you're learning. A lot of people want to do everything perfect before starting, but it's much better to start now, and improve as you learn.
Good luck and keep us posted with your results.