1) fill in printed forms, and mail out
2) fill PDF forms, print them out and mail out
3) use desktop software
4) use online software

1 and 2 only cost you mailing fee
with 3 and 4, you can either e-file (采用网络自动报税) or download/print/mail out

low income people may use 3 or 4 for free

there're many (online) consumer tax software. turboTax is the most popular and dominant. other main players include TaxAcr, H&R Block.

Main Federal Tax Form: 1040 with schedule A/B/C/D, and other forms

For Dr. Fang, he needs to fill in CA540 for California