Please note that I'm a UK author and intend the print version of my book primarily for the UK market.
Firstly, there are a number of questions you need to ask yourself. These might include
1. How do you want your book to be available? For sale through retailers (online or physical) or will you be selling it personally?
2. Where do you want it to be available? Locally, nationwide, worldwide?
3. How much are you willing/able to pay upfront for your publishing?
4. Is this a one off or are you planning to publish more books? In addition, might you want to publish books by other authors?
5. Are you intending to produce a small number of books eg for an organisation, or are you hoping to sell as many as possible?
6. Do you want to take full responsibility for your books or would you prefer someone else does it for you?
7. Do you want your publishing to include editing, proofing and formatting services?
Having considered the above questions, you should be able to decide whether you want to produce your book POD (print on demand, where each book is printed and sent out as it is bought) or by an offset run (you would usually need to produce at least 500 at a time to make this worthwhile. POD is generally cheaper to set up but more per copy while offset is more expensive to set up but subsequent costs are cheaper.
You will also need to decide whether you want to go with a self-publishing service (eg Lulu, Create Space, Completely Novel) or a printer (eg Lightning Source). Self-publishing companies usually offer a variety of packages and services. They usually cost more even if the cost is passed directly to the buyer. Printing companies give you more options of control over distribution and pricing but you will usually need to produce print-ready files and provide ISBNs if necessary.
I'm not going to suggest that any particular option is best, though I would urge authors to carefully consider the importance of producing something that is good quality physically, and competitively priced. And those factors will vary depending on what country you live in/who you envisage selling your books to. Don't just look at the big companies but consider eg small press publishers and smaller printing companies who are offering these things.
It's also interesting to note that the distinction between printer (especially if they are a printer/distributor) and self-publishing service is becoming blurred.
Many different publishing options are becoming available. If you want to produce a book, don't automatically do what you've done before or what your friends have done but take the time to research what is best for you.
And good luck!