Top 10 Pokemon

1 Dragonite D/O (good against anything but Articuno)

2 Tyranitar B/SE (good against Legend birds mew and mewtwo)

3 Golem RT/SE (Legendary bird killer)

4 Machamp C/CC (CC better for raids and counters TTar Blissy and Snorlax and some others)

5 Blissey P/HB (if you have a group of 19 in a raid... I mean lets face it why wast the revives and potions)

6 Moltres FS/OH (going to be a very strong fire type)

7 Zapados (going to be hte only relevant electric type)

the last three is all toss ups on what you have or don't have so I guess you can go with Vaporeon if you don't have a strong one yet or Lugia with the right moveset or even Articuno if you want to counter dragonite some day

Easy to get
Gyarados
Exeggutor
Alakazam
Eeveelutions

Medium
Rhydon
Golem- double rock
Machamp-double fighting

Hard
Dragonite
Blissey
Snorlax
Tyranitar
Lapras double ice

I would advise them to make an army of Machamps and TTARS to be honest.

1. Tyranitar-b/c or se
2. Dragonite-dt or db/o or h
3. Machamp-double fighting
4. Scizor-double bug
5. Golem-double rock
6. Rhydon-ms/eq
7. Jolteon-ts/tb or d
8. Vaporeon-at or go
9. Exeggutor c or es/SoB
10. Favorite fire type out of Flareon, Charizard, or Arcanine.

1 Tyranitar (Bite/Crunch)
2 Dragonite
3 Rhydon (double Ground moves)
4 Exeggutor (with Solar Beam)
5 Espeon
6 Machamp
7 Jolteon
8 Flareon
9 Lapras
10 Scizor

That should cover almost everything.

1.- Tyranitar (Obviously) B/ SE (Fast and powerful)
2.- Dragonite (The best generalist) DT/ O
3.- Golem (The best rock attacker) RT/ SE or RB (They're equally good)
4.- Gyarados B/ HP (Good against both psychic and fire type)
5.- Lapras IS/ IB (Definitely the best against dragons, IS is almost as good as FB in offense and that is her best defensive ms)
6.- Machamp (Obviously) C/ DP
7.- Vaporeon (I think this thing will never be obsolete) All moves but WP
8.- Exeggutor (Good generalist and the best weapon against water) C/ SB
9.- Flareon (Currently the best fire type and great DPS) FS/ O
10.- Scizor (Both Steel and Bug moveset have and will have great uses)

In this order:

1. Machamp (or you can't take gyms)
2. Blissey (for coins).
3. TyraNitar (for legendaries).
4. Dragonite (support your raid and gym teams)
5. Golem (for bird raids)
6. Lugia (generalist attacker)
7. Vaporeon (versatile, with good typing and great stats...Use it for raids and attacking and defending gyms).
8. Lapras (great defender that you can use for attacking as needed)
9. Snorlax (for gyms that have blisseys already)
10. Exeggutor (Great generalist attacker, specialist attacker into water, ground and rock mons, good defender)

With the current gym system, I'm not worrying too much about powering up defenders anymore. I've got half a dozen new defenders that I wish I could power up, but attackers take priority. Just attack a lot of gyms and use whatever defenders you already have or some high CP wild catches.

Others have covered attackers for raids pretty well. I'll add: I generally prefer charge moves with two or three bars. Solar Beam and Hydro Pump are great for unleashing massive damage on raid bosses and fully motivated defenders, but Seed Bomb and Aqua Tail can be decent alternatives if you are not good at dodging (so you can use your energy sooner without losing it) and are actually much better than one-bar moves on the second and third pass through a gym.

On the first pass through a fully motivated gym, I'll switch between two to three attackers, but after that use a generalist with a multi-bar charge move. One of my most used generalists is my Exeggutor with Confusion/Seed Bomb. (Current Extrasensory/Seed Bomb should work almost as well.) The mixed psychic and grass types provide good coverage against a lot of common defenders. For example, I frequently use Confusion to take out one defender, then use two Seed Bombs to take out a defender weak to grass.

Depends on the environment they are playing in.

1) Vaporeon can be brought to a good level cheaply, which is good for a lower level trainer. Good general attacker except against Grass and Electric, great against Rock/Stone and Fire.

2) Gyarados hits harder, and can be got with patience if there's a good water biome nearby.

3) Exeggutor, to take out all those Vaporeons everyone has.

4) Jolteon, to fight Gyarados.

5) Flareon, to fight Grass, Ice, and Steel.

Of course, if you're trying for Vaporeon, you'll get some Jolteon and Flareon too, so run with it.

At that point, they can start getting Golem, Rhydon, Dragonite, Lapras, and so forth. They will know what they need. Start with things that are attainable and are stepping stones to the top mon for attacking in raids, and PvP when it comes out, all the while hoarding stardust and candy for Snorlax, Blissey, Dragonite, Rhydon and Golem,

I would tell a noob not to power anything up until they hit level 25. Maybe 30. Have fun catching stuff. Save the dust. Get free or lightly defended gym spots for coins. What you catch and hatch will only get better.

I can't argue with any if what's been said. I'd add a Poliwrath with RS/DP to the list if you can evolve or find one. Mud shot/HP is also a useful combination.