Hi Jack, I depends on what level you are at, and is explanatory on those words and and abbreviations that are used., for someone new to DSLRs it is an easy read
To some just starting with an SLR it is a very big learning curve, so a book that starts with stuff that many of us have for second nature now is not a bad thing, how many go into stores like Jessops get a very expensive Canon/Nikon stuffed in there hands and after a very short time give up because they cant take shots like the professionals do, after all the idiot in the shop told them it was a pro camera, and they expect it to take the shots for them, Just press the button and it does it all for you, after all they were told it was the best bit of kit!
So in a "nutshell" if new to DSLR's learn before you make a big mistake and then say "This camera is no good".
I am not a good reader but I have just sent a load of my old books to a charity shop, They taught me loads, but I am still trying to get it right

Try this book from the Forum "shop" Magic Lantern Guides £15 for the K20.
It is written in good English and easy to understand.

Yes it is an ok lens the 50-200mm, I have one that will be going on Ebay shortly, I have the 55-300mm so not required now.

Don't bother not worth it,
Many others will also be watching that one, i take it it's the APO version, the one you are watching?
It just depends what you are prepared to pay for it, as for quality, the Pentax *SDM 300mm is a far better bet, but if you want a fairly light lens of that length it is fine, just make sure it is in good condition as it is not a “spring chicken” in age.

MP's claim for them as well, one claimed for 3 in a year
must have been a Canon user

Who make what cars these days is anybody's guess, Ford use some Peugeot engines (diesel) Renault and Nissan do the same with engines and other bits and the list goes on, so if a car suits you
forget the badge on the front of any thing, if the price is right (value for money etc) get it.
We have become too ready to oblige the advertising people, splash things in front of us enough and it will sell, kids today wont wear anything that does not have the the right label.
Also look at the TV adverts they must be spending a very large amount on womens "beauty" items, (because your worth it)for one.

Is that the type that attract ants and then stab them in the head and suck the ant body dry.

Or even one's floating duck island.

Even our MP's are doing it, and not just the odd couple of £'s they are doing thousands of £'s

Another reason for getting Sandisk is the recovery disc, an old friend Bernie accidentally deleted a card with loads of his images on, he formatted it I put it down to the old grey cells
Not only did we recover the shots he took but most of the ones before that.
Mind it should work (the recovery disc) with any make of disc.