The ideal form of removing weeds is manually, either by hand or using a long handled tool like a hoe, cultivator, weeding fork or oscillating weeding hoe,among the many other tools made for the job. Do it now, while they are still small, before they become large and spread out and control may demand more environmentally unfriendly means such as herbicides.
The UC IPM On-Line Resource Guide has a weed photo gallery to help you determine what kind of weeds you have (important if you need to use an herbicide).
It can also help you tell the difference between your reseeding annuals you have been waiting patiently for from last spring and those annoying sedges that are just starting to pop up! Just remember to put down a two to three inch layer of mulch to keep the weeds from coming back after you have worked so hard to eliminate them!