I would say you have done yourself by creating it in Photoshop. Firstly save a master copy of your file as .PSD file and store it safely, this is what you'll use to make any edits and create any other file format you require (also back it up somewhere).
The correct software would be InDesign for page layout, or, for single/double sided print, Adobe Illustrator would also be favourable.
However, you have created this in Photoshop.
Firstly add crops and bleed (as a photoshop PDF won't create crop marks or add bleed)
http://creativepro.com/photoshop-how-to-adding-bleeds-and-crop-marks/#
The best option is to save as PDF - try to get a ".joboptions" file from your printers. A .joboptions file is a preset of PDF settings that are user defined, a good printer will have a set premade that work for them.
http://www.designeasy.co/2012/08/how-to-load-joboptions-in-indesign.html
If you can't get these - then firstly I would not trust the printer - secondly - don't panic.
You can still do it!
In the PDF options from Photoshop select the PDF X4 option.
This leaves all colours as they are - there is no colour conversion. And it leaves colour transparencies in tact (or at least it should).
The correct place for any colour conversion to take place is the printers RIP (Raster Image Processor) - this is where your vector objects and any other information is converted to a very hi-res raster image.
You also want to make sure that black text is 100% black.
http://www.bittbox.com/all/photoshop-101-true-black-cmyk
You'll also need to ensure your document is in CMYK mode before making any text colour changes (or other colour changes).
https://forums.adobe.com/thread/285113
As you may gather - there's a lot to it. If you can't figure it out - ask your printer will they accept the Photoshop file and complete the PDF for you.
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Or if you like - you can request a forum member here to complete the file for you, at a fee of course.