I would say start from the poems 1913-1915 years – they are easier and a lot of them are well-known. My favourite period is 1918-1921, and second favorite is 1916-1917. The very early are just too flowery – and I was getting bored with the romantic adolescent angst (a good one!) even I was a teenager myself. After 1921 the poetry is very good, but more difficult to read, so not the best place to start. Also the progression is very interesting by itself. I, for some reason, has always perceived her poetry in colours and the periods I am talking about all have very distinct spectrums for me.