You begin figures with \begin{figure}[loc] where loc is a sequence of 0 to 4 letters, each one specifying a location where the figure or table may be placed, as follows:
A good way to put the figures where you really want them is to wait until you're done with the paper. When all the text is ready, you can modify it so it puts the figures where you want them.
Look for the end of a page that you want your figure to come after. For example: if you want your figure to go on page 77, find the place in the text, where page 76 ends.
Insert a \clearpage command there. This command will force LaTeX to insert all the floats (figures and tables) that weren't printed yet to be printed before any other text is processed.