Thank you so much Margo. I can't tell you how much I appreciate your help and for giving it without making me feel dumb. I'm so excited to get this part going. I'm really having fun making this quilt and I'm learning so much. I'm sure I'll have more questions because I don't have enough experience to feel as if I know what I'm doing. I wondered if It was a little late in life to start such an involved hobby, but maybe you can teach an old dog new tricks. However, I'm the first to admit that I don't seem to catch on as quickly as when I was younger. So many quilts, so little time and I'm about as slow as they come. Oh well. Happy sewing!

There are no dumb questions here! As long as you are careful to keep your folds and cuts parallel and perpendicular you should be fine.
Check your cut strips and if you notice that they are getting a little angle appearing in them, just refold the remaining fabric, cut a new straight line and continue cutting strips.
You can do this!

Sorry to be so long getting back to you Margo. I have just started in my sewing room. I don't know if I was subconsciously avoiding the dreaded task at hand or what. Thank you so much for your patience and guidance Margo. I finally held my breathe, said a prayer and cut my first sashing strip. Yeah!! I think it came out pretty straight. Can I continue to cut all the strips or do I have to square up my fabric after a few cuts? Hope that's not a dumb question.

I would suggest that you carefully press your fabric, then carefully refold the fabric, opposite of the way it comes off the bolt, so that the remaining selvage is lined up as if you were going to trim it off, then re-trim the side you have already cut. Use the lines on your cutting mat to keep everything parallel and perpendicular for a straight cut.
This isn't as accurate as cutting off the selvage that is lined up because there is a lot of fabric across to the other side, so be sure that you get each fold as smooth as you can. You can do this!

But I've already cut one selvage edge off. Do you think I can still fix that edge since it is crooked or do I just need to start again from the other side? I'm sorry to be so dense, I'm sure I am making this much harder than it really is. I thought I was supposed to refold the fabric with the selvages on each end of the fabric. In other words, folded the opposite way it comes off the bolt. Hope I haven't messed up my chance to cut the sashing on the lengthwise grain.

I use the horizontal lines on the cutting mat to make as many folds as necessary to get the length down to less than 24", which I can cut with my long ruler.

When trimming selvage edges to piece large pieces of backing fabric for a large quilt, I will carefully line up the selvage edges as I fold them, and then line the folds up with the vertical lines on the cutting mat, and use the horizontal lines on the mat to trim the selvage by moving the ruler several times to cut the length of the fabric.
I do have a large (30" s 60") cutting mat, so it's easier than using a small portable mat.

Hope this info isn't too confusing!

Thanks Margo. I'll try again. Do you fold twice since there are 2 yards of fabric? That scares me- it doubles my chance of cutting with a bend.

You get a "v" in your fabric strips if you fold your fabric to make the cuts and the folds are not parallel to each other.
When trimming off selvage edges of folded fabric, the edges must be aligned. Ironing helps if the fabric is wrinkled at all.

To cut straight strips from folded fabric, I use the lines on my cutting mat to make sure that all of the FOLDS line up with the horizontal lines on my cutting mat, then I use the vertical lines on the mat to make my cuts perpendicular to the folds. Viola! Straight strips!

Okay, my inexperience is really getting in the way. I started this project late and I have only gotten the first month's piecing done. I want to cut and fuse the letters for those sections now, however, I need to cut my sashing strips from the lengthwise grain first. I tried to cut the selvage off and ended up with a V in the fabric. Now I'm not sure what to do to fix the fabric. I'm panicked! Any suggestions, please?