I posted some things about Slann here:
http://www.dakkadakka.com/dakkaforum/posts/list/280771.page#1370209
That should pretty well cover that.
Like
mot characters there are a lot of ways to run them and some of it will depend on what you want to do. There are a million combinations for the various characters I won't go on and on, I will just list a few of each.
OldBloods and Scar-Vets run pretty much the same. The OB just has more points for kit, other than that, there isn't a whole much else they bring to the table. Most of the time, they will be better mounted for the +2 to armour. They can work well on foot as well. Also, if you aren't running a Slann, a Vet is good for the
BSB.
A great way to run a OB is on a Carnosaur, even if it is a large target. On one, he really needs an Enchanted Shield, though. An E. Shield also really helps for an OB on foot. The BBoC helps if you want the OB to go after heavy armour but the Scimitar is great for lightly armoured blocks. OBs should almost always have the Bane Head and Glyph Necklace. That makes the OB great at fighting other characters and living through it. A few examples:
OB; Carnosaur, Glyph Necklace, BBoC, E. Shield, Bane Head, L. Armour (455)
-- 1+/5+
Sv with a -4 to enemy armour and the Carnosaur attacks; pretty solid and dead killy.
OB; CO, Scimitar, Maiming Shield, Bane Head, L. Armour (280)
-- 1+
Sv with A8 is great in a unit of CoC or in a Saurus block.
Scar-Vets are nice a cheap and subsequently, great for bolstering Saurus blocks or CoC units. Here are some of my favorites:
Vet; CO, Scimitar, L. Armour, Shield (163)
-- best used in a CoC unit
Vet; BBoC, E. Shield, L. Armour (125)
-- nice in a block
Vet; SotH, E. Shield, L. Armour
-- also great in a block with
ASF
Skink characters are pretty bland, they have some decent options, though.
Priests are a must especially with access to EotG! A magic level is a must, unless it's a scroll caddy. The Diadem and CoF are fantastic options with or without a Slann. Some people like to give a mounted one the Plaque of Tepok but I am not a fan. I have been using a Priest with the Cube of Darkness lately and have just loved it.
Chiefs are really over shadowed by Scar-Vets. They have access to Terradons, which can make them great at flanking with a unit of Terradons. The only build I ever see used often is a Chief on an Ancient Steg with the Warspear. It's a solid build and does a butt-load of damage. I personally like putting one on a Terradon with the SotLS and an E. Shield. It's great at flank harassment.