I wont tell you how to skill up since that really depends on your own style of play but I can give you some general tips that might be helpful.

As a Dark Elf you have bonus fire damage, so a flame destro staff is going to be the key to your highest DPS. Skills with burning effects will only help in this area.

In terms of armour, 5 light is a good choice since it gives you all of the light armour passives around spell penetration etc. You might want to consider reserving chest, legs or helm for your 2 piece medium/heavy items though since they will give you the highest return on spell & physical resistance (making you tougher overall). As you level up undaunted having a medium & heavy mixed in with your 5 light will also give you higher max magicka, health and stamina which is something to look forward to down the track.

Typically in end game sorcs will stack their attribute points in to magicka and rely on wards (hardened ward, harness magicka, healing ward) for their survivability, this also frees up your armour glyphs for magicka. Overall as a sorcerer your DPS potential is based on three things in combination, your spell power, spell penetration and max magicka - the higher they are the more damage you can deal and coincidentally the stronger your wards will be. The rest is up to your bar skills and play style..