Hi Adam,
So you want to get started, and, presumably, using your transformer.
Not sure what current ratings apply to each winding, so be patient.
Most electronic stuff will require a power supply voltage of around 5 volt or less for logic circuits, and around 24 volt or less for general purpose stuff.
The 8.5 volt winding suggests a full wave bridge rectifier to produce around 10 volt DC which can then be regulated with a 'regulator' to give 5 volt or so. maybe even a +/- 5 volt supply.
The 44.5 volt centre tapped winding suggests a full wave rectifier to give around 28 volt DC which can be regulated to give up to say 20 volt DC.
The 38.5 volt winding is a puzzle and full wave bridge rectified will produce say 50 volt DC. This could also be +/- 25 volt.
Logic tends to use + 5 volt; Linear op amps tend to use +/- supplies up to +/- 15 volt DC.
So the traffo you have is a good basis for a general purpose bench power supply.
Its up to you now to say what you would like to have as a finished product.
I can say that you could have a power supply with:
0 to 8 volt Dc variable;
0 to 25 volt DC variable;
+/- 25 volt DC variable.
How does this sound?.
In the short term, forget about the iC's you have; just concentrate on the ultimate capability of a power supply based on the transformr.