Everything needs a beginning so let's start with a few pieces of advice I can offer - along with a disclaimer: My coaching experience has been with girls from grades 6 through 12, with the bulk of my time at the high school varsity/club level. We've won a few tournaments over the years, but no state championships and I doubt USA Volleyball will come knocking on my door...so take what follows for what it's worth.
Coaching is about plagerism. (Your high school english teacher is cringing right about now.) Ruthlessly copy from the other great coaches around you - drills, practice structure, philosophies, whatever - and then mold the material into something that fits your program.
You are a role model and leader. You set the tone for your team and the program from the way your players conduct themselves to their execution on the court. I coached in a very small town, and if I were to choose to have a beer on Friday night at the local pizza place. I would hear about it on Saturday from one of my players. You may ask "what's the problem - I'm not on school time?" The only way I can answer that question is by stating that I do not ask something of my players that I would not ask of myself. For example, there were times due to my "day job" that could I not be at practice exactly at the scheduled start time - therefore I gave my players limited leeway in the same respect. Therefore since I support the no-drinking policy, I'm not going to be seen tossing a few back at the local bar. As for leadership, my big epiphany came when I finally realized that my mood, my attitude, and everything else I brought into the gym affected the play of the team. How many of you have been in a match, or watched a match where a coach gave up on their team? Did you look at the players faces when it happened? You as a coach have far more influence than you think...
Practice should be harder than matches. It is a very difficult thing to plan and implement successfully, but if you go 200mph in practice while achieving your goals, then matches played at 100mph should be easy. It's not always the case, but it's something I try to work toward.
Keep everyone involved in the drills. I end up violating this at some point during every practice, but try to minimize drills where one person is executing the skill, while 14 others are waiting in line.
Relate everything to the match. For example, passing drills should be oriented to actual game play (baseline to net). I can't stand to watch a coach tossing balls to a setter with three hitting lines. When during a game does that ever occur??? Instead, toss to a passer (this is a good situation to get your libero reps) and make them pass to the setter.
At the end of the season, focus on the things that score you points. When district or regional tournament time rolls around, you should have a good idea what your team and players are capable of. Why spend time and energy on skills that will not be used? If I know we'll never run a back slide during a match, why spend time in practice at that time of the year to work on it?
It's about the players. It's not about the parents, relatives, significant others, or anyone else. You are there to educate and provide a safe, competitive, and fun volleyball environment. Be aware of what's going on both on the court and in the stands and manage both areas. I've been fortunate enough to only have to deal with one spectator issue since I started coaching. Unfortunately, I've witnessed dozens where a coach, referee, or site administrator has had to get involved.