It's good to know when it's dark. So i go to heavens-above, look up the Sun, and discover that it's 11:30 pm to 3:40 am. Short nights.
I often start out my planning by going to Alice's site. I listen to her Astronomy A Go Go podcast. She's got a very, very sexy voice, and i could listen to it for hours. Which is a good thing because her monthly show is an hour long. Anyway, she's a bit behind this month. Still, she has a chart of meteor showers. Right now is the June Bootids meteor shower, fairly bright. June 22 - July 2. Worth a look, right? If i can get out to dark skies.
She's got a link to Skymaps, so i download the current PDF. The first page has the map. It's got a calendar of events. The calendar has events like "on the 25th, the Moon will be next to the Beehive Cluster". I can find the Beehive without the Moon. And i'm pretty sure that i don't want to see the Beehive washed out by the Moon. But this may be really handy for beginners. Anyway, i ignore the calendar. I'd be more interested to find out that Venus is next to Mars (in the morning). So it might be a cool way to spot Mars. And Jupiter is next to Neptune. That might be a really easy way to find Neptune. The interesting thing is page two of the SkyMap. It has easy, medium and hard objects lists for the month - starting with Naked Eye. Just stars this month. Binocular objects are generally findable in my ten inch scope from my highly light polluted driveway. Telescope objects, not including galaxies, are also visible. I mostly look for things i haven't seen.
There are two good comets pages. Skyhound isn't up to date. The header says June, but the data says May. I move on. This other page is pretty cool. And it looks like a 8th magnitude comet is in Pegasus. I bring that up in kstars, a free planetarium program. Really, "sudo apt-get install kstars" is the easy way to get it for Linux. Stars down to 16th magnitude. Pegasus is visible most of the night. And kstars knows where this C/2006 W3 Christensen is, so i can print a field finder chart.
The Tools menu of kstars has a "What's Up Tonight" feature. The evening planet is Saturn. It sets around midnight. The morning planets are everything else. Mercury is pretty tough for me, as i don't have much of an Eastern horizon. But i saw Venus at 4:30 in the morning, and it was so bright i knew it was Venus without my glasses.
I switch to Comets, and look up Christensen. It transits at 4:30 am. That's only a bit after astronomical night ends. Maybe 3:40 is a better time to look.
The Asteroids list isn't very handy. Ceres is good. It's near Saturn in Leo. But if you look up Pallas, it turns out that it sets before it gets very dark. And Vesta is hopeless.
The kstars tools->Jupiters' Moons gives a chart. Usually i want to know which moon is which at some specific time. So, i set kstar's time, and zoom into Jupiter. Unfortunately, this doesn't work for Saturn. But Stellarium does this just fine. I don't generally use Stellarium, with all it's eye candy, to do planning. But this feature makes me fire it up. Stellarium has the feature that is works on Linux, Windows and Mac. And, did i mention, it has eye candy?
Back to kstars. Sometimes, i just set the time, and look at the Zenith. Boom. There's Hercules. M13 and M92 are always worth a look. But the whole line from Polaris to the southern horizon is worth thinking about. Ophiuchus is near there, and that's where Pluto is. So i look for Pluto. It transits at 12:30 am, at 30 degrees up. Not bad!
Or, i point kstars East, and see what's rising.
When i've totally failed to do any planning, sometimes i let my telescope's computer suggest things. It's got 12 objects per month. And nearby months are OK. Or i just ask it for clusters in some constellation that's high in the sky. Or maybe double stars. But now we're not talking free. Unless you think "Free with a $700 telescope" is free.