How put my original songs' melodies in note form on paper so that the melody can be played on an instrument. (I normally just play the chords on piano or guitar and sing the melody but I want the melody to be in written musical notes so it can be played.
Mary, As a guitarist and song writer, myself, I know what you want. I spent almost 10,000 hours on the guitar and on the serious study of music to get to the point that I could begin to write music. It does not come easy. It takes time, maybe less for you, maybe more. Sure, I hear there are musical programs that will write for you. Never tried them. But, as an artist it has to be yours. I also learned that the way you write your music does not make it written in stone. There are more ways than one to write a song and you may change it later to be closer to what you mean. Start where you are, study music theory also study songs. By that I mean, look at the sheet music of many songs and study the chord progression such as ii V I, or I, IV, V. Dissecting songs will be very helpful to you in understanding how others wrote great music and how you can. You will see in song writing that the chord progressions are used over and over so it is good to learn them. You will also study how the song writer used the various quarter notes, eighth notes, dotted notes, rests and syncopation. By seeing how they did it, you will begin to see these patterns in your own music. That will be your Ah Ha moment and it is cool to look a a new piece of music and say, I wrote that! It is a slow effort. If you want to write, realize it will take time, but there will be great rewards.
You'll need to learn the basics of how to read and write music from a book. That shouldn't take too long if you're not trying to do anything too clever.
I found with my early attempts at transcribing music that I would get the right notes, but the timing would be completely wrong. I might even discover that the music wasn't in the time signature I thought it was. The best solution I found for that was to enter the score onto my computer (I use MuseScore, which is free), and get the computer to play it back to me. It's soon obvious if it's not right.