Beets

Beets are really easy to grow.   Make sure you do not over seed. Just figure beets  need at least 8 square inches each beet. If you want good size beet root. If your after the tops you can space closer.  

   Beets in general are cold tolerant and will grow in any climate can be grown year round in zones 7 and above.  For those of you that are growing for market plant every few weeks from February thru September 

Beets should be succession planted.
Different planting instructions apply depending on which Zone you live in, for example, for Zone 6 & above, you are able to plant Beets from the end of January all the way until Thanksgiving, giving you a constant supply of Beets every couple of weeks depending on what your needs are, i.e. homesteading, farmsteading and the like. 
Things differ slightly for Zone 6 & below, ideally your last opportunity for planting beets would be Mid September and for best results, do not plant again until at least mid-March or when the ground has thawed.
The upside for Beets is that they are very cold-tolerant.
The key to good germination and harvesting for Beets is spacing, ideally they need to be at least 2-4 inches apart for salad beets and 4-8 inches apart for beetroot, planting at least 1/2 an inch into finely worked soil. 
It's vital to keep the seedbed moist and germination takes between 7-10 days. 
 30 days for salad beets to reach maturity and for beetroot, anywhere between 50-60 days to reach maturity.
Helpful Hint: for those who want salad beets and beetroot start with 2 inch spacing, picking salad leaves as you go leaves more room for the remaining beets to grow bigger.
**Please note if you're planting sugar-beets & mangels (livestock fodder), these should be spring planted, fall harvested as they take 90-100 days**