Start by greasing and flouring your bundt pan, I am paranoid about my bundts sticking so I am a bit obsessive about this step. I also got a nice heavy one and cool the cakes in it for 10 minutes before flipping them out. Then cream the butter and sugar. Next add the eggs one at a time.
In a separate bowl mix together the dry ingredients, which you may or may not want to sift, depending on how lazy you are feeling at that particular moment. Then add 1/3 of the flour to the butter and egg and sugar mixture, mix gently also known as folding, add half of the buttermilk (or if you are like me, the milk that has a splash of lemon juice in it or the powdered buttermilk route, where you want to put the powder in with the dry stuff and then just water for this step which looks a bit gross but works really well), mix, add 1/2 of the remaining flour, mix, then the rest of the buttermilk, mix, then the rest of the flour. (I don't know why I felt the need to spell out the alternating in that step for you....)
Next zest and juice your lemons into the batter and fold them in. I would highly recommend using one of these juicers, they work really well.
Dump the batter into the carefully prepared pan and bake for about an hour. Once the cake is done, let it cool in the pan for 10 minutes before flipping it out.
If you want, you can make a simple glaze with powdered sugar and lemon juice, I always end up estimating the measurements for glazes and then tweaking them to get them to the consistency I want. Slice generously and serve.