Welcome to the forum.
Unfortunately, you have posted to the Tips & Tricks sub-forum, which is a repository for articles on how to do specific things in Premiere. Maybe our MOD, Steve Grisetti, will move it out to the main forum for you, where it will be seen by many more, who will be able to offer ideas.
Now, here are my thoughts:
If you anticipate producing multiple DVD's, then PrE has no real way to do that directly and easily. Also, depending on one's computer, very large Projects tend to start bogging down.
To do Projects, where one will be creating multiple DVD's, the easiest way is to create a separate Project for each "segment" of your trip, and edit that footage. That also might be helpful in organizing your Assets. Then, when you have each segment done, you can Export/Share to DV-AVI Type II w/ 48KHz 16-bit PCM/WAV Audio, and then Import those AV files into "master" Projects, one per each DVD. This would be my choice of workflow.
Now, PrPro has a feature that could be beneficial with such a Project - Sequences. Think of these as "mini-Projects" within a "master Project." To give you an example of how these are used, I have an 8 DVD Project in PrPro, with 18 separate Sequences. Each is being edited separately, but within the single Project. When done, I will Export each Sequence to be Imported into my DVD authoring program, Encore, where they will be assembled into separate Timelines to burn to DVD. I have already created a "template" Project in Encore, as I will be using the same Menus in each DVD, and some other common Assets. I will just use that to start a new Project for each DVD, and Import the appropriate Assets.
Just my thoughts, and others might have some that fit your desired workflow better. Sounds like a fun Project!
Also, how long do you anticipate your final project will be?
Are you planning to cut it down to a single one or two hour DVD -- or are you planning to make a whole series of DVDs? If the latter, how will you divide them up? (Europe, Middle East, Asia, etc.)
You certainly don't want to cram all 26 hours of video into a single project. As Bill says, think in terms of segments. And, for best performance with the program, work on each DVD in ten minute segments, export each segment as an AVI and then mix these AVIs into 60-minute DVD projects. (You really don't want to cram more than an hour of video on one DVD -- if only out of consideration for your audience.)
I assume you're going to edit this video too. (With my videos, I usually only use about 10-15% of what I shoot.) So that too will be a consideration as you figure out your workflow.
I spent 10 days in Italy a few years ago. Shot hours of video. My final video was 45 very tight minutes long though -- and my friends and family love it! There's something from each day's adventure, and yet it moves along at a great pace. Remember, brevity is the soul of wit.
Finally, you haven't said what kind of camcorder you've shot your video on. That, too, will make a big difference as you plan your workflow. Some vidoe formats are much less efficient than others and, with this much raw footage, the last thing you want to do is have the whole thing come crashig down on you because you've got too much going on at once.
Great and useful comments.
Also, thank you for moving this out to the main forum. I was going to drop you a PM, but got tied up on other things, and you beat me to it!
If your source files are DV-AVI, then one challenge might be hard drive space - at roughly 13GB per hour, 26 hours of DV-AVI would require almost 350GB just to store it. Given the importance of the footage, you'll probably want to back it up, too (on a separate physical drive, of course) so you'd be talking 2 drives with collectively 700GB just to store the raw footage. And that's before you start editing!
Another thought is to capture each tape into multiple physical files instead of a single file. For me, it makes hard drive management easier, seems to make PrE run much smoother, and I find it easier to find clips (YMMV). I've used Scenealyzer to automatically do this as part of my capture for quite a while, so I don't remember what PrE does natively. One 60-minute tape will typically produce around 100 files.
With that much material, the PrE Project Archive function may come in handy, too. Project Archive will create new files that contain only the footage you actually used (it also saves still images, audio, etc). So, for example, if you have a 1GB source file but only use 10%, Project Archive will create a new 100MB file, and you can then delete the original source file and free up 900MB. Again, you'll probably want to make sure your original files are backed up and never touched, and Project Archive will probably be something you want to do when you're 99% sure you're done, but it can be an effective tool at managing the space on your working drive.
I love Steve's advice about keeping projects small: export each small project to a DV-AVI and combine those individual DV-AVIs into a master project at the end. The size of each project is inversely proportional to how upset I'd be if the project got corrupted. Sometimes a "project" might be a little 30-second "music video" clip that took hours to perfect.
One last thought is: somehow keep track of what you do as you do it. With so many source files and "mini-projects", it can become fairly easy to get lost after a while. I have a spreadsheet that has project name (e.g. HomeMoviesDVD1-project1.prel), what it is (Kyle's 10th birthday party), the source files I used (tape20-0051.avi - tape20-0065.avi), the exported DV-AVI output file location, comments, and even columns to check off things I always want to remember to do and always forget (e.g. go back over the finished project and make sure the audio is at a fairly consistent level). I have an icon on my desktop to make it easy to always open the spreadsheet while I'm editing. A simple sheet of paper would work, too.
Just my thoughts.... happy editing... sounds like a fantastic project!