PPI and DPI are two different things and shouldn't ever be confused. (The only reason knowing PPI is useful in PhotoShop is to get a rough idea on screen when using View>Print Size zoom function. And most modern monitors are in the range of 96 to 140 PPI rather than the ol' 72. But other than for on-screen comparison it doesn't really apply.)To know how big you're going to have something for a given resolution is under the print settings. However you can set image size by dimensional units at a given DPI. (However if somebody changes the DPI later on, then the scale will be out of whack. Also DPI may not always carry through with an image if somebody is printing from a file format such as .jpg. Make sure the person doing the print job knows how to configure their printer settings to change DPI, and inform them of which to use when printing.) For most purposes a DPI around 150 to 200 is ok for a quick print job and gives reasonable quality, if you need high-quality and can work with bigger resolutions then a setting of 300 to 600 DPI should be ok. But remember, if it's for print - don't work with pixels, work with measurement units set a DPI that's reasonable for you. If the template shows up not to scale, then resize it until it fits.

Also when dealing with print, odds are it's never going to be the same as the screen on the first run. If you're looking for a certain degree of quality, then running a few proofs is and will always be a necessary evil. (Do one run, compare, adjust CMYK levels, etc. And repeat until it looks right. This is also why adjustment layers are handy - you can turn them off during the comparison and back on for the print run. Once you're golden, then in most cases you're set for the bigger run.)

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Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.