Directing
I think that it would be very difficult to get good results if everyone on the crew were first-timers. If you are a first-time director inevitably you are going to be a little nervous and make mistakes. There are going to be so many things that are unfamiliar and new skills to learn, so you are going to need some seasoned pro's around you. The two most important are camera and sound. The rest you can have as new-comers. You are going to need someone on the clapper-board and someone recording the takes... so in my view, the absolute minimum crew is five (including yourself).
A shooting schedule is essential. Everyone must know what scenes you are shooting on each day. Also, a shot list (of every single shot and the order you want to take them in)... otherwise, under the pressure of the shoot, you will forget essential shots. I'm not sure that you need a story board on a small shoot, particularly if you wrote the script. We spent a month drawing one and then discarded it after 10 minutes!
Readings (cast reading out loud the script, not strictly a rehearsal) of the script are a must, and rehearsals can be invaluable. But don't expect the cast to be able to give 100% cold. During the shoot, do allow the actors to improvise a little after you have got your shot. They might come up with something even better.
Directing is tiring. On the shoot, it might be tempting to go out with the crew at the end of the day for drinks... you are having a great time and enjoy their company. If you do go, it's a very good idea to leave early... this production rests on your shoulders. Also, get some great shoes and a big heavy coat/a hat, if it's Winter. You're not going to be thinking well if you are uncomfortable and cold. Speed of thought is crucial when directing.
Make sure the takes are properly recorded in a notebook/scene-taking sheets and have a description of what the shot was about. The better the written record of your takes, the faster you can get through the initial edit process of capturing the best takes.
Monitors are invaluable. They give you a real feel for the images you are capturing and if set up properly, they show the exact image... which the view finder sometimes misses. Headphones for sound are also good, as they get you close to the action and cut out distractions.
'Crossing the line' needs to be understood (there are plenty of books which explain it). It is not complicated with just a few actors but can get trickier when you have a larger cast. 10 years ago the cost of film and processing was huge. Now the costs are negligible, so use plenty of tape. Get like Stanley Kubrick and have a 10 or 15 to one shooting ratio. And don't say cut when the performance has finished... let the editor have plenty of tape either side of the take.
Get yourself a portable chair. You will need to rest your feet/legs/brain from time to time. And don't worry about the cast having to wait around a lot. It's inevitable and your job is to get the best shot possible. Ultimately, the cast will thank you for making a great movie, not for letting them go home 10 minutes early.
It is inevitable that you will have a bad hour/morning/day. You have to lead from the front, especially when energy levels are flagging. Sometimes you need to have a little laugh and a joke to raise spirits... sometimes to bring the tone down when people are having too much of a good time. Learn to know when to step it up and when to bring it down.
Even though you are the boss, you mustn't be afraid to let cast and crew have their say. It is collaboration. But it is a very delicate balancing act... it is not directing by committee. There are always time pressures and you must keep to the shooting schedule as closely as possible. So sometimes, you won't have time to take on board additional input. And if someone isn't performing, think why? Can you do anything to help? And if you do "need to have a word" always, always, always do it in private.
Sometimes you will get it right on the first take, sometimes on the tenth. Don't ever move onto another shot because you are bored with trying to get it right... you will really regret it in the editing room.
The more alternatives you have in the edit room, the better the end movie. Make sure you have lots of cutaways and talk to your editor before the shoot. Pick his/her brains about the scenes you are most worried about. In an ideal world, I would actually consider having your editor on set - it's a bit radical - but boy, would he/she understand your movie that much better if they had actually been there! Certainly, make notes for the editor as you shoot because you will forget key changes that you made to the script when shooting... and why you made them.
