Many sites on the Internet offer to host your portfolio. Most offer a basic free version and charge a small amount for something a little more advanced.
An online model portfolio is the option of choice for agency-independent freelance models and probably the cheapest and easiest way to create a portfolio and attract the attention of photographers for prints for time, time for CD (PFT and TFCD) or paid work. Just don't expect agencies to take much notice.
Creating an account and uploading your images is, in most cases, a very simple process.
You still need professionally produced photographs. Snapshots taken with your little digital camera or your mobile phone just won't do.
Go for a large, reputable hosting provider, such as OMP or Musecube. See what other models have created and then try to make your pages better.