Yes, I keep a calendar of what I have planned for each blog. I am thinking or re-working, but for now I plot out what day I want each post to hit and then plan back from there. I created a spreadsheet to keep track on a weekly basis. I like keeping my weekly calendar for blogs as a written version with some things online because sometimes i just need to write stuff out instead of updating online.
I keep a schedule- I wake up early to work before my toddler wakes up and work during nap time. If my schedule is busy, busy then I work it out with my husband to work at night or on the weekends too. Then again, I am trying to do this as a career.
I have a rough, pseudo schedule in my head. Early in the week a post about creativity, mid week a post about me or an observation etc, end of week Featured mom. Weekends are free flow and somewhere in between I post giveaways. I'd like to be more structured than that but I tend to go with the flow. At the moment, I contribute very lazily at only one place so it doesn't require a schedule - if it did, I'd likely leave!
I have certain topics that I hit on certain days. I try to blog, read my favorite blogs and get as many comments in as possible, while my daughter is napping. Then, in the evening, I will hit the computer while hubby is on his computer. I have a new addiction to twitter. So, that is in the mix. I use twhirl.
I am a fairly new blogger and have been taking blogging mostly at my own pace. I've been spending time online every day after the kids are in bed, and I'm going to try and put something new on the blog one to three times each week. It *is* a challenge, especially when I want to include photos (and I'm planning a video too). Some of my time online is just reading about blogging and playing around.
That said, I think you should go with the inspirations you have when you have them... if that makes sense, and then just reserve time in your daily routine to be able to write -- if you have no urgent drive for a particular topic, then you can rotate through which blogs need the most attention at the time.
Good luck! I want to start one or two more blogs and have ideas (and want to continue some private blogs for my kids) but it is hard to spread yourself around.