Hello. I've never done a thief/assassin/stealth type character in any Elder Scrolls game.

Particularly for Skyrim, what skills/perks should I focus on? How should I distribute my health and stamina points upon leveling? I want to be able to sneak/steal/pick locks and kill people.

If there are any useless perks I should avoid that info would be appreciated also.

Ermmmm after retiring my level 61 Bosmer assassin, i would say essential skills are :

• Sneak ( all available perks )
  
• Archery ( probably at least 8 perks )
  
• Light Armour ( until you at least have the windwalker perk )
  
• Alchemy ( poisoner )

Any other skills are really subjective to how your style of play is. I was almost no magic, so focused on a bit of one handed as well.

Wear light armour, sneak almost everywhere, build up your 'combat' perks early (Archery n backstab). Dont bother with lockpicking or pickpocketing perks, instead build up alchemy and make fortification potions. Health and Stamina equal split for the first 30 or so levels, then a bit of magika. You'll need stamina to pull off those critical one hit archery kills.

First off, thanks for the info.

I forgot to mention I will not be using magic. I hate using magic.

After level 30, what is the reason for needing points in magika?

This very much depends on your skills as a player and your preferences in battle. Too many permutations to give you any good advice.

But I can tell you this:

Focus on the Sneak perks. Take them all.

Pick either One-Handed or Archery and perk those up according to your preferences, but whichever you take focus on the damage-related perks (Armsman and Overdraw).

Don't bother with any kind of magic. Don't bother with Heavy Armor or Two-Handed.

You do not need Alchemy unless you want to use poisons or make your own potions.

Allocation of Health and Stamina is largely dependent on how you use One-Handed or Archery. If you use power attacks or lots of zooming with the bow, increase Stamina, otherwise increase Health.

Oh, finally: join the Dark Brotherhood.

I used 'almost no magic' not none at all, and felt Alteration was fairly sneaky with the detect life/ detect undead spells, so used it to pre plan attacks

Sneak and One-Handed are key. Light Armour should be your prime armour choice, but is not necessary. Archery can be used to raise your effectiveness at a distance. Alchemy can be used to make your strikes more deadly. Illusion can be a useful complement, as it grants useful spells like Muffle and Invisibility, and can turn enemies against each other.

One man's water is another man's poison..... there are probably hundreds of different ways to be a sneaky/assassin/thief and each will be unique to the next

This!

I can only tell you how my thief assassin was.
I used
Marksman:almost all the perks(I didnt use any one handed)
Sneak:again almost almost all the perks,but you only need one stealth perk.
Alchemy:almost all the perks again.
Light armor:A couple of perks is all I needed( you rarley get hit)
Pickpocket:for the poisoner perk and extra pockets is nice,it made thieving fun.
Lockpicking:a couple of perks,mostly just for role playing though.

As for health and stamina.
I kind of like alot of stamina so I split the points 50/50 until I hit about 250 stamina then I focused only on health.

You certainly don't need any magick but if you decide you want some you can take out the pickpocket,lochpicking and lightarmor perks for all the Illusion perks.
With Illusion you won't really nead armor but you will need lots of magicka so focus points something like 2/2/1 magick,health,stamina.

I know you said you don't like magick but I through it out there just in case.

One handed is a good skill also but either pick one handed or archery as you have a difficult time leveling both.

Something I liked to do was to play with consequences.
If your caught pickpocketing or any other crime I either went to jail or ran like heck.
I never liked the I'm a thane option or just paying your bounty off,it doesn't seem realistic to me.

But most important
Happy killing

When I play an assassin, I generally go with this layout for my primary perks:

Sneak: Stealth 1/5 (Because anything more in this perk, really is wasted I feel as far as payoff goes, course I also use the other perks to branch into other skills), backstab, deadly aim, assassin's blade, muffled movement, light foot, silent roll, silence, shadow warrior

Light Armor: Agile Defender 5/5, Custom Fit, Unhindered, maybe Wind Walker

One Handed: Armsman 5/5, Dual Flurry 2/2, Dual Savagry, Fighting Stance. You can move into Bladesman, which I do sometimes for the benefit of swords just in case My sneaking does not cut it.

Archery: Overdraw 5/5, Eagle Eye, Steady Hand 1/2

I think those four skills there give you a nice basic groundwork to work from as far as essential weapon skills go. From there, considering this is at level 34 I think you can easily add in some Alchemy, Enchanting, Pickpocket, and Smithing if you wish. OR if you do decide to go with some magic, mix in Conjuration and Illusion.

First of all, I want to say that Illusion supercharges any assassin. Invisibility, Muffle, quiet cast, and the ability to extend an escape by Calming or terrifying adversaries... I won't do without it.

Be that as it may... Sneak is key. Max it. And so is getting your paws on DB shrouded gloves. They turn a sword or war axe into a weapon of mass destruction, and a dagger into armageddon.

Archery is useful for long-range kills. One-handed is essential. And Alchemy can make some great poisons, or potions to fortify your sneak skill even further. Don't bother with two-handed or Destruction (no stealth bonus for either) and heavy Armor will make you noisy. Use Light Armor; the Guild and Dark brotherhood make some useful ones.

You all rock. Thanks for the advice.

SEems like a fun build to play. Going to be fun to branch out a bit.

Thanks Baelor I was just getting ready to start another character.
She was going to be a hunter but thanks to this thread she just switched profesions
This time though my assassin will focus more on dual wielding daggers,this should be fun.