Plug the card into the adapter, then plug the adapter into your PC.
Open computer and save all the files you want to keep as you will lose them otherwise.
Next, left click ONCE on the card to highlight it in the main computer view where it shows you your drives and storage spaces. Then right click and select format. Click restore device defaults, and click "quick format." Then hit start format, it should only take a few seconds.
Once the format is complete, you can move the files you kept back onto the card.
On the taskbar, there should be a small icon by the system clock that looks like a usb stick with a checkmark on it. Left click it and select the eject option. If you don't do this, eventually you will end up with data corruption and need to buy a new memory card.
Now you can unplug it from your PC, remove the card, and put it in your droid.
I never had a Blackberry, but if it can be connected to the PC and be recognized as an external storage device, then you can simply copy the date onto the PC. After purchasing your Android phone simply install the micro SD card and format it. After it's been formatted you can move that data back on to the micro SD card.
Note that if the data files are not compatible with any Android app, then they cannot be accessed at all. For example, say you have an app to track expenses on your Blackberry, if you want to be able to access it in Android or on the PC, then you need to save/convert that data in Excel format