Assuming you actually fly from from A to B, it is indeed a treasure trove you are missing on
You can find out more background if you google on e.g.
tephigram explanation
here here etc. A tephigram and a skew-t are a similar thing. The former is a British term; the latter is more American.
I am no expert on this but they are invaluable for getting a grip on cloud
tops, for IFR flight. Somebody who understand them can also work out the stability of the atmosphere by comparing the actual lapse rate against the adiabatic one, or whatever. I just use them for cloud tops, and use the SigWx for other stuff.
The temp / dewpoint spread tells you the probability of cloud formation at that level. I have the following from a UKMO forecaster:
< 1C means 7-8 octas cloud
1-2C means 6-7 octas cloud
2-3C means 4-5 octas cloud
3-5C means 2-4 octas cloud
>5C means clear
Forecast ones can be found
here (look under Animated Soundings). Actual (past) ones can be found
here (select Europe / GIF-skew-t...). The former site is the only one I know of that does forecast ones; most of the time it is reasonably good. It gets its data mostly from GFS. The UK Met Office does not publish this stuff.