I'm currently learning guitar and started out with an electric guitar that came pre-strung with .010's. I'm wondering if learning with .009's is much easier to learn chords. Is there a benefit to starting with the .010's?
Also, if I swap the .010 for .009 is it likely that I'll also need to adjust the truss rod? I've read that it's unlikely, but how will I know if I need a rod adjustment after swapping?
It is true that lighter strings will require less finger strength and less exertion to press the strings down onto the frets. If you are struggling with barre chords to get enough pressure on the strings to make them play without muting some of the strings, it is possible that lighter strings will help until you build up strength and or improve your technique.
However, the disadvantage to lighter gauge strings is that they will flex more and might make strumming and picking more difficult due to greater deflection of the strings and could also contribute to unintended bending (fretted string pushed out of parallel with other strings making note sharp) when stretching for certain fingerings.
As Tim mentioned in his excellent answer - before doing anything, be sure your guitar is properly set up. For easiest playing you want the action to be as low as possible without causing fret buzz.
Many folks mistakenly believe that the first thing you should do to lower the action is to adjust the truss rod. That is not always the case. The truss rod is there to counter the tension on the neck exerted by the strings. Without a truss rod, the neck would bow in so much that the action (relief between strings and frets) in the center of the fretboard would be way too high. Ideally you want an almost straight neck with a slight concave curve to provide a little relief in the center of the fretboard and to be sure none of the strings are so close to the frets that they contact them while vibrating causing buzz.
But before you adjust the truss rod, you might want to check the string height at the bridge/saddle. Most electric guitars will allow you to adjust the height of each individual string at the saddle/bridge. Some may provide for pairs of strings to be adjusted simultaneously instead of individually. The action of your guitar can be changed by adjusting the string height at the bridge.
After adjusting the saddle height for the strings at the bridge, you can then check the relief by holding down the 6th string at the first fret and the fret where the neck joins the body and make sure there is some clearance at the frets in the center of the two frets you are holding down. If there is not enough clearance you would loosen the truss rod to allow the string tension to pull the neck into more of a concave bow. If there is too much clearance you would tighten the truss rod to straighten the neck against the string tension. Always make very small 1/4 turn adjustments at a time and give the neck awhile to react to the new position before continuing.
For a better understanding of how the truss rod works check this answer on Stack Exchange Adjusting Truss Rod after changing to lighter strings
If you make any adjustments you will also want to check and possibly reset the intonation. Setting the intonation is a subject in and of itself. You can find information on adjusting intonation and how string gauge affects intonation here How Does String Gauge affect Intonation? and here How to adjust intonation
If you are able to lower the action with the existing strings, going to lighter strings may not be necessary. If you still want to try lighter strings, you will need to re-check the saddle height, relief and intonation again after changing to lighter strings.
Finally, often problems getting fretted notes to sound clean are as much about proper technique and hand/arm position as the action or string gauge. If you are not taking lessons from a qualified teacher, at least have one check your technique to be sure your hand/arm positions are optimized for the various chords you are trying to play and in general.
Good luck - and enjoy your journey towards becoming a guitarist.
Lost count of the students that I changed strings from .010 to .009 and even .008. But that's not the whole solution. There's the action, which may need tweaking, even (especially) on a new guitar.
If you're struggling with new barre chords, that's a couple of ideas. Another, specially if you only play by yourself, is to do the almost obligatory tuning down, a semitone, even a tone. This can bring about unwanted rattles, so is a double edged sword,.Your teacher (what do you mean, you haven't got one) will guide you.
There is no point in showing off your battle scars - they shouldn't be there in the first place! It's also possible that you are pressing down on the strings too hard anyway - often happens with beginners, and I see it in intermediates, too.
Adjustment? Wait a day or two, sight down the neck, spot how much bow there is in it, compared with the dead straight strings. But there won't be much difference between .010 and .009s. Obviously, do the check before changing anything. It may show that's where the problem is anyhow.
I suggest you play on the strings for at least a few weeks and then move down a gauge if your barre chords are difficult or painful to play clearly. I started on acoustic and didn't play barre chords for a while, so I'm glad you're off to a balanced start. I've been playing for 12 years on and off, studied music education, but I really don't know much about electric guitar, so I asked the best guitarist I know about the truss rod. He said, "Just loosen a quarter turn!" like it was no big deal.. this makes me worry about my poor little electric :P This is my first post so I just signed up and thankfully my friend sent me a correction just in time to catch this. He said, "I lied, tighten a quarter turn please!"
in summary,
Do what feels right
Bleeding fingers are a sign of progress
Tighten a quarter turn if you do go down a gauge
