That's just a personal decision based on your current situation. If you feel that you have to do a nights/weekend program while working, and there is not a nights/weekend RN program, do the LPN program.
I feel that getting your LPN first definitely makes RN school much easier, and it's easier to get into an LPN to RN program than it is to get into an RN program off of the street.
However, if I had to do it all over again, I would have tried to skip LPN and go straight for the RN. I had to go to LPN school 40 hours a week for a year with only 3 weeks' total for breaks. Compare that to 12-16 hours a week for two years for an ADN, and it just makes a lot more sense to do an ADN or even a BSN at those hours if you can swing it with your work schedule and you're not in a "gotta get it now" mode regarding a nursing license.
I do like the fact that I've kind of worked my way up through the ranks, as it were. But, I really could have used an extra couple of years of RN pay instead of LPN pay.