We present an overview of accelerator mass spectrometry (AMS) radiocarbon sample preparation and measurements, describing the technical upgrades that now allow us to routinely obtain 0.2-0.3% precision for l-mg carbon samples. A precision of similar to 1 % on samples with 100 mu g of carbon can also be achieved. We have also developed graphitization techniques and AMS procedures for ultra-small samples (down to 0.002 mg of carbon). Detailed time series are presented for large and small aliquots of standards such as NIST OX-I and OX-II; FIRI-C and -D; IAEA-C6, -C7 and -C8; and C-14-free samples.