For the Newly Called

Where does the choir meet, and at what time? Make sure that the building's custodial bishop has your choir down for that room at that time for the entire year. Express to the Bishopric member that you would like a time that doesn't conflict with presidency meetings, youth council, linger-longers, or any other ward auxiliary.
How often would the Music Chairperson like the choir to sing? What is her philosophy of appropriate? There's quite a range of viewpoints, from "hymnal only" to "Latin is OK if it's in a happy key."
Is the Bishopric willing to fill any of the following callings: Choir Accompanist, Assistant Director, Choir President, Choir Librarian, Choir Member. There's a range of viewpoints on this as well. Even if it's just you with the calling, don't worry: There's still lots you can do to make a lovely ward choir.
Is the Bishopric willing to give the Ward Choir a budget? Be prepared with the projected cost of, say, three new pieces for the size of choir you expect, and with a synopsis of the current music situation, based on the content of the libraries.
Ask if the Choir will be allowed to raise funds for music. Also ask if the Choir will be allowed to have a yearly retreat/workshop, if you're interested in doing one. Ask if you may recruit choir members in the program, in the auxiliaries, and -- missionary work is important, too -- in the community.

3. Come up with a rough schedule for the year. No need for music yet, just themes: Two pieces for Easter, a special Christmas Program, a youth number for the Sunday before Pioneer Trek, etc. Plan a choir retreat, if desired. Plan a recruitment drive for fall and after Christmas, if desired.

Using the vague details of your schedule, talk to former choir members. Seek out and document all the instrumentalists in the ward as well: They read music and therefore make great recruits, to say nothing of the possibilities of adding their instrument to choir performances.
Show up in Priesthood Opening Exercises with sweets and handouts. Pitch choir: "We need 3 more men for our Christmas Program. All warm bodies accepted." Do the same in Relief Society if necessary. Don't discount the youth. Any child over 8 is a good candidate for choir, but the teen-agers can be fantastic . Be mindful that the boys will have unpredictable vocal ranges from about 12 ish until 20. They require a little more care, but it's worth it to them and your choir.
List choir rehearsal times in the Sacrament Meeting program.
Listen during congregational singing for valuable voices. Approach potential recruits as being needed to fill a specific need, and provide an expiry date: "We need a strong tenor for this arrangement of "Abide With Me" we're singing in March. Can you help us for a few weeks?" Then make rehearsals worth their staying on.
When Home Teachers ask if there's any way they can help, let them know that being in the choir is the best way to help you for the time being.

Let the Bishopric drive the frequency of performance. Then you can choose music that is easily worked up in that number of rehearsals.
Match the music to the choir: For the experienced, well-proportioned choir, SATB is appropriate. If you don't have anybody who reads music, consider some unison and two-part music. If twice as many women than men, you should do SAB arrangements, regardless of their ability level. Mind the accompaniment: If it's too hard for them, rehearsals will bog down and the accompanist may find a reason to step down.
Use instruments when possible: The local piano teacher, high school music director, or neighborhood composer will gladly sketch out an extra line for your ward's bassoonist, harp player, or string ensemble.

Start out the rehearsal by telling the choir what you're going to do that rehearsal.
Arrange seating(or standing) in a way that allows singers to hear each other! Being able to hear other singers has a powerfully positive affect on rehearsals, and prevents vocal fatigue.
Start each rehearsal with warm-ups. By the end of warm-ups, singers should be limbered, both physically and vocally.
Rehearse a familiar piece first, then the more difficult ones. End rehearsal with something familiar.
Avoid soliloquy, and avoid any one singer sitting silent for more than a couple of minutes. If possible, keep everybody singing every moment. For example, just because the altos are learning their line by rote doesn't mean the whole choir can't sing along in their octave. Better yet, let the Sopranos sing their part, and have all the men sing along with the altos an octave lower.
End the rehearsal by telling the choir what you did that rehearsal, and how they did.

It's best to meet a little early to warm up and go through the music.
Practice beforehand in the chapel, standing where and how you intend to sing. Smaller groups may benefit from standing in two rows equidistant from the podium microphone.
Decide beforehand if you intend to dress similarly. I warn that choosing to do so may affect participation levels, and have the potential of embarassing a person who forgets.
Decide beforehand how your choir will approach the podium: Will you all sit throughout the meeting on the stand, and stand in unison to perform? Will you sit together in the pews, then come up for singing? Will singers sit with their families, then come up to sing?
Notify the person in charge of the program. Know their submission deadline.

There are many ways to manage rehearsal items. I have numbered, assigned choir folders, which are carried in a box to and from rehearsals. Each piece is numbered to match the folder, which makes missing music easy to track. With the folders at home, it's easy to add and remove music from the choir folders, and having the folders pre-loaded saves rehearsal time that would have been spend passing music around or collecting it.
Recruit a choir president. Assign that person to call choir members each week to remind them of practices and performances.
Recruit a choir librarian. Assign that person be responsible for preparing, distributing, and collecting music.