I'm wanting to play a different kind of character than I'm used to, and I'd appreciate some input on it to help me build it with out missing some key portion that will render me ineffectual. I've played a mage, and a shooter; now I was hoping to play a "thief". I figure that a character like this would likely end up as an Elf, so I was thinking of some B@E skills, stealth, gymnastics, some face skills, perhaps a smattering of computer skills.

I'm really not absolutely sure how a character like this works, so I'm not sure what all is needed, or where to start. Thanks in advance for any help you can give me.

A nice tart would be a high Agility and Reaction as this i what the Stealth group runs off of.

Skillwise, Definatly the stealth group, some in the athletic group and points in the hardware computer and lockpick,
should allow you access to most places. Possibly some Hacking kill and programming to let you screw around with.

equipment will vary from player to player but checkout the runner gear section in arsenal, particularly the disguised objects section. but make sure you get the electronics toolkit as that will be essential for a lot of your work, and an autipicker maxed rating.
Armor will pretty much have to be a chameleon Suit or have the chameleonic upgrade from arsenal

Actually, your skills will depend on what type of thief you want to play.

Are you the charming swindler, talking rich old ladies out of their life savings?
The quick fingered pickpocket, lightly lifting valuables out of marks pockets?
The second floor man, good at breaking into houses and small companies?
The mugger, thump to the head and steal everything on em but their boxers?
The professional jewel thief, highly focused on getting into the most sucure areas?

Think about exactly what type of theft you did in your characters packground and build up a skill set to support that.

Yah, Agility would be good. Keep in mind Climbing and Running link to Strength, not Agility, and you might want to climb if you're a B&E type, so don't use Strength as an uber-dumpstat(though it doesn't need to be through the roof, and a Synthacardium can help with the rest.)

For self-defense, a style which gives bonuses to Surprise attacks(might be nice to knock someone out silently if breaking in.)

Computer skills are good, and perhaps some good ol' fashion lockpicking.