and one of them was how to hide fields from the edit or new form in sharepoint lists, so i found how and im gonna share it, also there's a message from Karol who motive me and bring me to the right way of sharing my knowledge, thanx again.
finally, im not sure if it will help you, but for me it does.
first of all, you must open the site in sharepoint designer, go to the desired list and for example check in the EditForm.aspx, and after open it.
Now you will have that view :

Now, you must hide that control to bring another one customized.so to do that, right click on the form, property of the webpart component, a popup will flaunt, go to disposition (second grouping), and check hide option.
after you complete that, in the menu bar, go to insertion, sharepoint controles and go to the fourth choice (customize form list ...), now another pop up will appear, select your list name in the first dropdown and select elemnt in the second, after check how you want sharepoint designer to generate you form (edit, new or disp), and now you will see your form customized and ready to submit any changing from you.
our propose is to hide a field. select the fiel you want to hide, in parallel the code concerned will also be selected, now just delete it or put it as a commentary (between , like in html), now the rendered form will appear without the field :).
finally save the form, and check out.
i hope i come acroos your problems, and it will help you in your career.
