There are two ways (that I know of) to do it.
One is to use a purpose made sheet of paper with fabric fused to it - you can purchase these at Joanne's or other craft stores. The fabric has already been pre-treated to accept and retain the pigment from ink jet printers.
The other is to use your own fabric, pre-treat it in a special solution so it RETAINS the ink from your ink jet printer, then fuse it onto freezer paper to print. The pre-treating can be done with a product called BubbleJet 2000 ... there are also some "make it yourself" recipe's online but I was unsuccessful at finding the ingredients so I purchased the BubbleJet.
Now ... if you are only printing with black ink, you *may not* need to pretreat the fabric. The reason is that SOME ink jet printers use dye for black ink, but pigment for colors. The fabric will retain the dye, but not the pigment. You can test this easy enough by making a test sheet with black ink and laundering it several times.
To make a test sheet (un-treated) .. simply fuse (iron) the fabric to the shiny side of a piece of freezer paper. Then cut the freezer paper to a size your ink jet will accept (mine will accept 8 x 5 - some machines will only accept 8.5 x 11). Print the page ... let set at least 30 minutes ... peel fabric from freezer paper ... iron to set ink.
If you need color, the full instructions for pre-treating and post printing handling are on the bottle of the Bubble Jet 2000 product.
Regardless of whether you use untreated fabric (for black only), pre-treated fabric, or the purchased fabric sheets ... DO NOT use on a laser printer. Fabric printing should only be done on an ink jet. The heat of the fuser could set your fabric on fire.