Succession planting

Hi all. This is my first post here being a newbee to veg growing.
Last year I started a small veg plot to grow the crops we like and eat a lot of. I divided the plot into 3, following crop rotation advice, to grow potatoes, onion family and peas/beans (I am not really interested in brassicas).
Whilst I was fairly pleased with the results in the first year, it seemed to me that I could have done better with a bit more planning and experience. I want to make fuller use of the space i.e. when I dig up my early potatoes what can I plant in their place? Likewise after the onions have been harvested, what next? What can follow the peas/beans etc.
Hope this all makes sense to you experts!
Looking forward to your advice

 

Thanks for that, really helpful.