Getting them into the canner without a mess
Your jars are packed, the brine's in, and now you've got to get them into the big pot without dumping hot vinegar water down your arm or knocking a jar into the sink. Sounds like a nothing lesson until you're the one standing there with a hot jar and tongs that don't fit, panicking a little. Let's not be that person.
What you actually need
A jar lifter. Not tongs, not a spatula, not "I'll just use a towel." It's the rubber-gripped tong that clamps around the neck of the jar. Costs about four dollars and it is not optional. I'm not selling you anything, I just don't want you dropping a jar of hot pickles on your foot.
You also want your canner rack already in the pot and the water already hot. Not boiling necessarily, but hot. Lower a cold jar into cold water, fine. Lower a hot jar into cold water, or a cold jar into already-boiling water, and you risk cracking the glass from temperature shock. Get your water heating while you finish your jars so everything's moving the same direction, temperature-wise.
The actual lowering-in part
Here's where people psych themselves out, and it's just this:
Pick the jar up with the lifter, gripping right under the neck, below the threads where the lid sits. Keep it upright the whole time, don't tilt it. Lower it straight down into the rack slots. Don't drop it the last inch because you got nervous and let go early, that's how jars crack on the bottom of the pot. Set it down like a full cup of coffee you don't want to spill.
One jar at a time. I know the water's hot and you want to be done, but rushing is exactly how a jar slips sideways and you end up with brine everywhere and a burn on your hand. Slow is faster here.
Space the jars so they're not touching each other or the sides of the pot if you can help it. Water needs to get all the way around each jar. Full batch and it's snug, that's fine, just don't stack anything.
The steam thing
Once the jars are in and the water's heating back up, keep your face and arms away from directly over the pot. The water itself isn't what gets people, it's the steam. I burned my wrist years ago reaching over a canner vent, never touched the water, just reached through the steam coming off it. Left a mark I wore a bracelet over to a wedding because I didn't want to explain it. Steam's sneaky. It doesn't look like anything, and then it's on your skin and you understand why they call it a burn and not a "warm surprise."
So reach in at an angle, not straight down over the middle, and take your time.
Once they're all in
Make sure the water covers the jars by at least an inch, sometimes recipes say two, check what yours called for. Add more hot water from a kettle if you need to top it off, don't dump cold water in on top of hot jars.
Put the lid on the canner, bring it up to a full rolling boil, and that's when your processing time actually starts counting. Not when you put the jars in. When the water's actually boiling.
About that first batch of jam
This isn't jam, obviously, we're deep in pickle territory now. But it reminds me: my very first batch of jam, before I knew anything, never set. Stayed liquid, like peach soup. I was so embarrassed I poured it over ice cream all week and told Brett it was "peach sauce, on purpose," like I'd planned it. He knew. I knew he knew. The point is the mistakes you make starting out are rarely dangerous, just annoying. A cracked jar or a botched batch is a bad night, not a bad summer. Don't let the fear of messing up make you tense on a step this mechanical. It's tongs and hot water. You've got it.
One real opinion while we're here: you do not need to sterilize these jars separately first. Processing time of ten minutes or more, which pickles almost always are, and the boiling water in the canner does that job. I sterilized every jar by hand my whole first year, an hour of my life I'm not getting back.
Before next time
Find your jar lifter, or buy one if you don't have it, and practice picking up an empty jar a few times before you're doing it with hot brine. Cheap rehearsal, saves you a bad moment later.