If you had opened the 'scroll' map piece earlier, you probably just would have had to have the 4 pieces in your inventory to open the way further into the cave. The game apparently does not accept them as meeting the requirements until they have been opened (which makes sense, since the maps are suppose to be what guides you to the cave in the first place).
The maps and site I linked to were made by Kiya (though a few of the screenshots there were by Dragon). While I don't see anything particularly wrong with them, she did start off using Photoshop, which is overkill and a bit cumbersome for someone with no previous graphics experience (plus it saves with crappy jpg quality).
I use a combination of CompuPic and a few other graphics programs for editing and annotating screenshots. My final save is always done in CompuPic, as it has the best image quality per file size of any graphics program I've tried (it is also very good at resizing, cropping and adding text). I have a few other programs that are better at adding arrows, or circles (etc) to images, or which support layers or other various features.
Kiya switched to CompuPic after I posted about it and a few other programs (link below), though by them she had most (all?) of the screenshots done for her DD site. Actually, I've collected a few more graphics programs, but have not gotten around to trying them out yet in any detail.graphics programs, for editing screen shots
- there is a second set of program reviews in a reply to the original post
For the initial screenshot, and any interim edits, I always use a lossless format. The screenshot function built into DD saves as a jpg in the original release, and as png in a patched or already updated game version. I usually use PNGShot if I need a bunch of screenshots, though. I have a couple screenshot program
names saved to try out, sometime... maybe I'll get around to that before D2:DE is released.
For your walkthroughs, can you not just add the plain screenshot, and then overlay that with arrows and text in the pdf file? That should allow better text quality (especially when zooming in) and the text would remain editable and movable. The graphics file could also be edited or replaced without loosing (or even effecting) the text. I have not made any pdf files myself, but that is my understanding.