Assuming you mean fashion modeling, there really isn't all that much to know; shows like ANTM are nonsense. It is very simple; if you are 5' 9"+, 34-25-34, with long legs, a reasonably pretty face, and no visible deformities, you are so, SO very rare that you can almost certainly get modeling work. No school, no portfolio necessary.
If you are not all of that, you almost certainly cannot get modeling work. No amount of determination, wishful thinking, modeling school or professional portfolio photos will change that.
You just need to send the standard set of audition photos to any agency (no posing, no background, full body shots front, side and rear in a simple black or white bikini, and front, side and 3/4 head shots, hair up, little or no make up). Virtually all modeling work is in NY, LA, Chicago or Miami. Anywhere else you'd only be working part time, as little more than a hobby.
Ignore anyone telling you about alternative modeling (petite, commercial, whatever). No one does that type of modeling as a job. There is no work for that type of model. Period. Commercial models are not models, they are actresses. And we all know how virtually impossible it is to become a wroking actress.
Petite modeling does not exist. Look at any website; you'll see they use the same model, in the same clothes, for both the regular and petite versions: http://www.anntaylor.com/catalog/search_command.cmd?form_state=searchForm&searchTerm=woll+jersey+twist&searchKey=KeywordSearch&searchMode=mode+matchallpartial&navState=0&didYouMeanFlag=1&callingPage=/catalog/product.jsp?productId=28770&N=1200023&pCategoryId=3940&categoryId=198&Ns=CATEGORY_SEQ_198&loc=PTLP&defaultColor=Black&defaultSizeType=Petitehttp://www.brooksbrothers.com/search.process?q=non-iron
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