One thing I do is to cleanup bulky lines after I get it working. For example, I might use $LOOP = $LOOP +1; until I get comfy and then go back and change that to ++$LOOP;.

In this case, the first thing I noticed was chomp: chomp (my $current = <STDIN>);.

Also, I keep the input and descriptor together.

print "Type the current of the circuit.\n";
chomp (my $current = <STDIN>);

print "Now type the resistance of the circuit.\n";
chomp (my $resistance = <STDIN>);
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But, really, as long as it's legible and someone can pick this up after you've moved on and edit/use it, you're a step above some people. Keep It Simple, =!Sloppy.