Don t worry about your old books! Since v3, Delphi hasn t changed much. This is why most of the programs compiled with D3 still compiles in D7 or even newer versions. And if it doesn t compile, probably you need to change a line or two, here and then.
I would recommend you to search other VERY simple components on Internet and see how they are made. Then make your own and post it here. Let other take a look at it and suggest improvements or spot bugs.
About your control s design:
1) maybe you DON T need those two labels. You can just paint the text directly on the image. If you have lots of those components as you say, you may save a little bit of memory.
2) you may NOT want to have lots and lots and lots of images loading in one form. The overhead may be significant. What you can do is to load the pictures ONLY in images that are visible on screen - and you will put on screen ONLY 5-10 images (or whatever number of images you can show on the form without going out of screen). As the user scrolls down, you keep the same same TImage controls on screen but you load new (next) images in them.
3) You may not want to store labels and TImage in an array (I suppose it is an TImage because it seems you want to show them on the screen else you won t need labels - you need to explain your problem in more details if I got it wrong). But you can store a TBitmap and the text (that you want to display in labels) instead.
So, you may need to calculate how much CPU/disk overhead your hundreds of controls will create and how much memory they need. If you stay well under 1GB and the loading time is under 10 seconds, then it is relatively ok. IF not, you may want to think about your control s design before starting to actually implement it.
Hope this was helpful.
See ya.