The best watermark fluid is Ronsonol lighter fluid, for the old fashioned metal re-fillable cigarette lighters, and it's a fraction of the cost of the "specialized watermark solutions". I and many other collectors have used it successfully for years. On some foreign stamps that were printed with what is known as "fugitive ink" any solution will ruin them as the ink will combine with the solution and run off the paper, hence the name. These are listed in stamp catalogs with a warning about using solution on them, but I am unaware of any US stamps printed with that type of ink, and I've dunked 10's of thousands of them, just make sure you aren't smoking, around any open flame, and in a well ventilated area.
Instead of purchasing a special watermark tray, usually only about $1, but still $1 saved, is to use a clear glass ashtray, pyrex bowl, or something along those lines, and just place it over a black piece of cloth, paper, anything black, and it will work as well as the trays they sell for this. Also watermark fluid can be saved after use, if you have a glass container with some kind of airtight lid. It doesn't take much though to see the WM's, and might not be worth the hassle to you to save it after use. I'll run a batch of stamps through at a time, and them pour off any remaining fluid into one of those little airline liquor bottles to be used again, but I'm a cheapskate.
Looking at your stamps, I don't see anything spectacular, but it is definitely the nucleus off a collection. When you pull a stamp off the album page, you want to peel the hinge that it is mounted with from the album page, and not from the stamp, as that can damage it, and make a thin spot on it's paper surface which detracts from value. You then will need to soak the stamp in warm water for about 10 minutes, and the hinge on it's back, along with any paper will float off. The next step is to dry it, and you lay it facedown on a towel laying on a flat surface. If you lay it face up, with the design showing, the stamp will dry and curl into a small tube, and you will have to soak it again. It will dry in an hour or 2 depending on temp and humidity. Then you will want to keep it in a paper envelope, and it will eventually flatten out. You can speed this flattening process by doing what is known as pressing, and you put the stamp in an old hardback dictionary, the ink on these won't get onto the stamp, but most other books, except a bible printed on India paper, will bleed ink from the printed letters onto the stamp and ruin it. Then just leave it in there a couple of hours and it will be pressed nice and flat.
Only other thing I can think of you will want to get a pair of specialized "stamp tongs", and even my cheapskate self have never found a substitute for these. I've tried tweezers and they absolutely will not work right for stamps, and even have a tendency to do damage. I have the old school steel stamp tongs but understand they are being made of plastic too now, and are less expensive than the metal ones. Handling stamps with your bare fingers is okay when you are soaking them, but once they are dry they will absorb oils from your skin and degrade, also fingers are pretty clumsy compared to the tongs when handling dry stamps once you become accustomed to them.
Good luck with your stamps!