Step 1: Setup your page
1. Open Adobe Illustrator
2. Create a new page with dimension:
3.370(W) × 2.125(H) inch. This is the international Credit Card size which is also considered as a default size for business cards. However, now a days designers use different sizes for business cards such as- 3X2 inch, 3.5X2 inch etc.
3. Color: CMYK
4. Resolution: 300 dpi
Step 2: Design
1. You can now draw or type anything in the stage such as- name, title, company name, address, phone number etc.
2. If you want to use photo/image, or apply some design effects, you can use Photoshop. Just make sure the exported image is in 300dpi(for better printing). Exported image could be in jpeg/png/psd/tif format.
3. Type everyting(name, title, company name, address, phone number etc.) in Illustrator for smooth printing.
Step 3: Prepare your file for final printing
1. Export the file as
.eps/.ai/.pdf. .eps is mostly preferred.
2. Make sure all the texts are "Create Outline" (Select all and then Ctrl + Shft + O; O for owl). Create outlined makes all the texts into a object which is not editable anymore. Otherwise you might get a call from a press that fonts are missing or get the business card with their choosen fonts-Comic Sans MS

3. If you use any images then make sure those are embeded in the .eps file.
4. You can use
Bleed and
Safe area to avoid unexpected results. Check this post from here:
http://distortedesigners.com/forum/view ... f=67&t=728
5. Write the CD and send to the printers
You are done!
Hope this will help. If any question, feel free to ask.
best wishes