Welcome Aboard!
Depending on which version of SH4 you've purchased, you likely won't need the Patch. The Patch takes it from the original version to 1.5, which fixes some earlier problems and adds U-Boats to the mix. If your version is a newer one it comes already patched and ready to go.
We do like to hear ourselves talk, so feel free to ask any questions you may have. Also take a look around the forums, as we have a lot of different interests and most of those are represented here.