Most people have covered their planting areas with cardboard, to stop light getting through, and then with weed fabric for the same purpose and as an aid to keeping the cardboard in position. Let the darkness do its work.
As soon as convenient you should order muck and add it to your beds. On the course we laid out beds at 120cm wide (4' wide), covered with muck, and paths, covered with woodchip, at 60cm wide (2' wide). Remove the weed fabric, add the muck and woodchip on top of the cardboard and replace the weed fabric. One load of muck (£35 at 2022-23 prices) should be enough for a half plot of 125 sqm. As a guide we used this amount on the half plot 251A back in early March; aim at a rate of 4 full barrow loads for a 10m long bed, adjusting the number of barrow loads according to the length of your beds.
There is no need to rake off any dying vegetation. It will rot down.
In the Spring it is best NOT to uncover your beds all at once. The longer that you can leave them covered the better. Uncover just one bed at a time, a few weeks before you need to use it. Use this couple of weeks to fork out any large weeds such as docks and comfrey and hoe off any annual weeds. The beds won't remain weed-free for long as there will be some persistent perennial weeds, to be removed with a hand fork, and lots of annual seeds, which should be hoed off every week - hoe before they are visible! Some weeds, such as bindweed and oxalis, don't appear at first because of their life cycle, so be prepared to hand fork such weeds throughout the season.
The relatively fresh muck is not ideal for first plantings so I would suggest that you expose a narrow row for your planting of modules, say 10-15cm wide, by moving the muck to one side. We used this relatively fresh muck on 251 in early March and it was great for our beans, courgettes and squash. We used older muck, stored at the front of 162, for earlier plantings on 162. This would be a good regime for future years.