I don't have them all mapped out in Pines (also not at a computer I can install it on) but here's some general bits.
While leveling, particularly solo, you want one or two of the rifle powers, photon grenade and either burst or blast. It GREATLY increases your dps and makes up for the idiot ai of your bots. After 32 (when you get Upgrade), I respec down to just Photon. Photon gives you aoe pull to grab the attention of things while you are hiding in shadowfall, otherwise you have to stand on top of them to body pull or set at least some of your bots out of bodyguard mode. It also gives you damage and cc. (side note, get one of the bind sets to give you fine control of which minions are doing what, the bind sets are what make MM playable). Once you have your Patron/Epic pool powers you can consider dropping Photon in favor of pulling with those powers. Personal preference.
I consider Leadership: Accuracy a must. There's some argument about it because MM gets one of the smallest numerical advantages out of Leadership. Since you have the pool, I recommend taking Maneuvers as well for the Defense. Assault you can take or leave. It's a minimal bonus and you can't slot anything interesting into it. I've been enjoying the new Victory Rush (it didn't exist when I was playing on live), particularly once you can take bosses while solo since it's bonus is dependent on the rank of the dead minion you cast it on. If you do take assault no more than two slots, you can't put anything in it.
I like Hover for additional defense, though it's yet another end draining toggle and before you start racking up accolade and set bonuses running 6 toggles (3 leadership, shadowfall, darkest night) can start to lead to serious end issues and popping LOTS of blues. But ultimately travel powers are personal preference. Hover can also put you in the middle of your bots, but above them for various auras.
I like Soul Mastery because it fits thematically so well and give lots of nice cc, debuff and more personally controlled damage.
Repair is a trap for /dark. Don't take it. Once you have both Protectors healing and Twilight Grasp you shouldn't ever need it.
Black Hole is a pain for groups because it slows you down. If you are doing pure solo content and want to try larger packs maybe take it to cut the incoming damage in half. You'll get yelled at for using it in any League sized content.
As a single target, no damage hold, the only reason I see to take Petrifying Gaze is to stack hold magnitude with another hold to take out a nasty boss+ level mob. You don't have another hold until patron/epic level. This is why it's last.
I'm considering switching from hover/fly/tactics/maneuvers/assault/victory rush to hover/teleport/recall friend/tactics/maneuvers/victory rush, that's why things are listed the way they are below with the slashes and just 'Travel'. Order only matters for when you exemplar down. Take what you MUST have when doing Ouro content first. Having sprint and ninja/beast run makes the travel powers less necessary.
Many MM swear by Provoke, I haven't found it necessary, but there are apparently some very nice tricks you can pull with it and selectively keeping only some of your pets in bodyguard mode.
As you accumulate inf, all of the unique set IOs for your pets are a MUST. You can rack up 20-30% defense and resistance for your pets (this depends on whether you go Supreme versions of the MM only sets).
Hope this gets you started! Bots/Dark if fun and powerful. (Noisy though, expect complaints about your noisy noise bots stomping around from some teammates.)
Up through 32 (slotting suggestion after)
1 Battle Drones (6)
1 Twilight Grasp (6)
2 Pulse Rifle Burst (up to 3, but you're specing out of it so whatever)
4 Tar Patch (5 or 6)
6 Equip Robot (1)
8 Photon Grenade (5 or 6)
10 Darkest Night (6)
12 Protector Bots (6)
14 Howling Twilight (1)
16 Shadow Fall (6)
18 Tactics/Travel
20 Fearsome Stare (6)
22 Travel/Tactics
24 Maneuvers
26 Assault Bot (6)
28 Assault/Victory Rush
30 Assault/Victory Rush/Travel 2
32 Upgrade Robot (1)
After 32 respec
1 Battle Drones (6)
1 Twilight Grasp (6)
2 Tar Patch (5 or 6)
4 Darkest Night (6)
6 Equip Robot (1)
8 Photon Grenade (5 or 6)
10 Howling Twilight (1)
12 Protector Bots (6)
14 Tactics/Travel
16 Shadow Fall (6)
18 Travel/Tactics
20 Fearsome Stare (5 or 6)
22 Maneuvers/Travel 2
24 Travel 2/Maneuvers
26 Assault Bot (6)
28 Assault/Travel 3
30 Victory Rush
32 Upgrade Robot (1)
35 Night Fall
38 Dark Servant
41 Soul Tentacles
44 Dark Embrace
47 Soul Storm
49 Petrifying Gaze
