I like to make books to publish with Blurb, and I like to have full creative control of the process and work offline. They have some lovely software to download, apparently, but if you click "not on Windows!", it offers you another version of the software and the button changes to "not on Mac!", and if you click button that it goes back to "not on Windows!". Sigh. So, for those of us taking the third linux-y way, we have the wonderous Scribus.
I'm no expert, but I've done this twice now, and thought I'd post the settings and steps that worked for me.
First a disclaimer:
I'm no photographer. I don't care much for colour profiles except ones that make it work, and I don't much understand what I'm doing in that department. I post settings here that have worked for me, and make no guarantees they will work for you. My monitor is certainly NOT colour-calibrated.
So, here are the steps I go through to make a book with Scribus and Blurb.
1) Assemble all your stuff in a folder. Plan your book thoroughly by sorting a rough layout and choosing what goes on what page. You could do this on paper, or I like to make a rough layout in something like LibreOffice Impress. Anything quick to plop in some pictures. This step helps you find how many pages you'll need for your book and I can't stress how important it is to know that before starting! I can't imagine the bother if you decide to add more later and blurb decides your measurements need to change and you have to re-tweak the positions of all your images. Gah! Although probably it wouldn't change by too much and maybe you don't care about image positions to the nearest pnt...
2) Find out what your book measurements will be. This is on the "PDF to book" section of Blurb's website, and you need to "get specs". You'll be invited to choose things like paper-type, book size, number of pages and cover type. Remember which you picked because you have to tell Blurb what you chose when you come to upload your PDF. I print this page to file for easy reference during the design process. By number of pages, Blurb means printed sides of paper, not leaves of paper, and it has to be an even number to include the first page on the right when you open the book, and the last page on the left as you close it. Reminds me of the argument with my husband over what constitutes a "round of sandwiches". Anyway, I like to work in points for measurements and so does Scribus.
3) Set up your Scribus project for the pages! Since blurb uses single pages not traditional signatures, so choose "single page", then how many single pages you want. First page is set to right. The width and height should be set to the page size/trim line as your finished book will be, the extra bleed space is added with the "bleeds" tab. Note that when working on the pages, the coordinate (0,0) is at the top left of the page trim, inside the bleed area. The absolute top left of the pdf page will be (-x_bleed,-y_bleed). Finally, I set margins so as to define the safe boundaries. You're done, and Scribus displays your pages nicely side-by-side as if you opened the book: great for sorting those double-page spreads.
4) Set up a separate Scribus project for the cover. I use single page again, and add guides to show me where with spine and flaps are. Add these under Page>Manage Guides, and take heed of the co-ordinate system as noted above.
5) Set up colour management for each of your projects. First obtain the Blurb colour profile from here. Copy it to /usr/share/color/icc and re-start Scribus. For each project, activate colour management from File>Document Setup>Colour Management. I have RGB images, colours and monitor set to sRGB, and CMYK colours, images and crucially the printer set to the Blurb profile. The other settings I left as "perceptual", "relative colourimetric" and blackpoint compensation on. My images I left as RGB, some of which have embedded profiles (from the digital camera), some do not (from my scanner). You can find out more about your images using the ImageMagick tool, see this page.
E.g. to find if there are any profiles:
identify -verbose myimage.jpg | grep 'Profile-.*bytes'
... omit the grep part to just see a load of stats about the image, including which colourspace.
6) Make your pages and cover. Scribus is nice in that you can see image resolution as you scale the image, so you can be sure not to reduce it too much below 150dpi. Scribus also has some cool effects you can apply to your images (e.g. greyscale), but beware that the PDF/X-3 standard that blurb requires does not support transparency. I have got round this in the past by working out how to produce the effect I wanted using e.g. gimp, then flattening transparency (removing the alpha channel to just get RGB) before exporting as an image to stuff into Scribus. I think this is Image>Flatten Image in gimp.
7) Export as PDF. File>Export>Save as PDF. Under the GENERAL tab, ensure you choose PDF/X-3. Under the Pre-Press tab, make sure you tick "use document bleeds" to ensure they're added to your PDF page size. Failure to do this will result in Blurb rejecting your files with page sizes that are too small! Under "Output Intent", the output profile should be set to the Blurb CMYK profile you downloaded earlier.
8) Preview and double-check your pages and cover documents as PDFs. As well as checking content, check page size. I've found that some readers (Cairo document viewer) show the wrong page size, but the right colours, while others (adobe reader) show the right page size but crazy colours. You can get adobe to show measurements in points under Edit>Preferences>Units.
9) Upload to Blurb and cross your fingers for a happy pre-flight check.
Final tip: with having full control of the book design, it can be tempting to go wild with all the possible effects. I note that this does not lead to a more exciting book, but a rather scrappy unprofessional one with no uniting theme. I recommend to pick a style and stick to it religiously. Exactly what I didn't do with my last book, and it shows ;-) Remember: more fonts does not a better document make.
Hope these tips might be useful to someone out there! Happy bookmaking.