A W7 form is a form you fill out in order to request an Individual Taxpayer Identification Number, if and only if you do not have a Social Security Number or do not qualify for one.  When filing you must include the Form W7, the tax returns which the W7 should go with.   Also you need to include your certified copy of your drivers license and passport.  The certified copy of your drivers license can be obtained by your DMV office.  A certified copy of your passport can be obtained through the passport office with a notarized letter and a check or money order made payable for the current fee.  This may take some time to gather, but it can be done by going straight to the office in which your identifications were obtained.  You will need both of these or your license and a visa, you must show proof of identification and proof of nationality and legality.  After you have filed for your ITIN it should take about 8-10 weeks to receive your number.  Which country are you from and I can help you find the specific information for the passport certification, as all countries are different.  

You may obtain a certified copy of your passport, certified by the agency that issued the passport. Complete Form W7 and attach the certified copy and send it to the address on the W7 instructions. The tax return(s) for which you applied the for the tax ID must be attached to Form W7. It usually takes 8-12 weeks for the IRS to assign the tax ID. If you engage a professional to be the certified acceptance agents, you do not need to get your passport copy certified. You may visit them in person with your original passport - they will prepare Form W7 and W7(COA) and attach a photocopy of your passport and submit with the tax return(s). 

You may obtain a certified copy of your passport, certified by the agency that issued the passport. Complete Form W7 and attach the certified copy and send it to the address on the W7 instructions. The tax return(s) for which you applied the for the tax ID must be attached to Form W7. It usually takes 8-12 weeks for the IRS to assign the tax ID. If you engage a professional to be the certified acceptance agents, you do not need to get your passport copy certified. You may visit them in person with your original passport - they will prepare Form W7 and W7(COA) and attach a photocopy of your passport and submit with the tax return(s).