Hey JThomas nice to meet you,
Jelqing requires a partial erection. You should probably be looking for a 40-60% erection. You should alternate the hands, when one hand gets close to the top you should already be starting to attach your second hand. Start off doing it for 5 minutes at a time and work up pretty quickly to more time (around 1/4 hr). Ensure your penis is properly warmed up prior to starting (with a warm wrap). Do another warm wrap at the end of your routine. Make sure each stroke lasts around 3 seconds (count one - one thousand, two - one thousand, three - one thousand).
You need to take it easy as you start but if you do not have an increased flaccid hang for some time after jelqing you are probably not doing it hard enough. The penis changes quite a lot during the first two months of jelqing. It develops more vein capacity and becomes more resilient.
If you haven’t read the FAQ, your should check it out.