Not sure how to answer this question but I'm going to suggest that you find the pace that works for you.

I'm not a very fast runner but I'm good at endurance. I average around a 10 min/mile pace during training and a 9 min/mile pace on race day (on a good day).  So, for me, 10:30 min/mile would be comfortable for that kind of mileage. But I also haven't done much speed work lately either (planning to start soon). The more speedwork you do, the better your pace will be. But again, it depends on you. I know there are plenty of regulars on the board who would run circles around me at that distance but that's what's comfortable for them.

Speedwork helps to increase speed, but pace is something that has to be practiced over time to allow your body to adjust to it at that mileage.

Your question doesn't include enough information to give an answer.  Obviously the pace for running 10-13 miles isn't the same for everyone.  What is the right pace for me or for an Olympic athlete are two different things.   So there is no way anyone can tell you, based on your general question, what pace is right for YOU.

Your best way to find out the right pace for YOU, would be to look at a training pace calculator which takes into account your current race paces and translates that into training paces for different distances - and also for speedwork.  The one I've used is http://www.mcmillanrunning.com/mcmillanrunningcalculator.htm   Bookmark that link because you'll refer to it a lot as a runner!

(In other words, +1 to BOSNPM's answer above!)

Are you running on a treadmill?  From the way you describe your pace in mph that's what it sounds like.

There is still no one answer to what is a "good" pace except what is good for you and your abilities.  If you are training to place in races and you need to know how you compare to others in your age group, then you can look up race results from some recent local races and see where you fall.

The McMillan training pace calculator that we mentioned before will calculate your training paces based on the speeds you are running now.  If you run a 10K in 52 minutes, for example, then the suggested "long run" pace is 9:49-10:49  (Most runners, BTW, speak of their pace in minutes per mile rather than miles per hour.)  The distance of a "long run" is open to interpretation - for some runners 12 miles is a long run, to a marathoner it would be more like 18-20 miles.  But there is a range to work with in the suggested paces.

You talk about being new to running - you talk about being a distance runner - you talk about increasing your pace - you talk about pushing yourself to the max.  And then you talk about not wanting to get injured.  So keeping those first four things in mind, you need to decide what your specific goals are.  Do you want to run a faster 5K or do you want to conquer new distances?  Because your training will reflect your goals and especially as a newer runner you need to focus on those goals one at a time, not try to do everything all at once.  THAT is how you will avoid injury!

Well.. its a quite open question. The answer is very simple: the pace you feel comfortable. Me I know that I am very comfortable with a pace of around 7 minutes and 30 seconds per mile for a half marathon. It really depends on you. A little advice, I would suggest you not to bother too much about it. Just train, take notes of all your trainings distances and times and just see your progress. That's where your focus should be if you are relatively new.

Its not that fast if you consider that my partner of training went under 1h20 . Its a good 16 minutes faster. heh

Anyway, if you want a nice tool to have a visual follow up of your trainings and progress, check out www.mapmyrun.com