BE sure to remember DO NOT leave your cutting mat and/or rulers in your car or any where that they may be exposed to heat or sun. They WILL warp, and are virtually useless then. ASK ME HOW I KNOW!!
If you can afford it I would recommend purchasing Eleanor Burns' square up 16"/16" ruler. It is marked well and you can make a large variety of different sized blocks. I have that one and also her 9"/9" and love them both. I would also recommend the Spring action scissors by Fiskars. I bought a pair on sale and love them. I recently purchased another pair to have as a spare. I have a few pairs of very expensive Ginghers that I've had for years and love them, but I really like the spring action Fiskars and find I am using them more than any others. The are very sharp and cut through very thick layers. DON'T use your quilting or sewing scissors for anything else and keep them out of sight from family. People who do not sew, think scissors can be used for everything. But if your quilting scissors are used for paper cutting and everything else, you will need a new pair very soon.
I would also recommend purchasing some blue painters masking tape to use when you are preparing your quilt for sandwiching the batting, top and backing. It works well and doesn't leave a sticky residue. I also use this on my machine when I want to mark a stitch width quickly.
REMEMBER to keep your machine cleaned and oiled - just as you would your automobile. When I oil mine, I let it sit for a day a least so I won't get oil on any of my fabric.
Another thing to remember, is let your family - children especially know that your machine is not a TOY and is off limits to all. Little ones find them fascinating and can quickly get injured with the needle, through a small finger and they love to play with the tensions and buttons on the machine. My two children grew up with me sewing, I started when I was nine, so they have always been around my sewing, but knew from the beginning that my machine and scissors were OFF LIMITS. If they wanted to sew I was always there to supervise, same with cutting. They always asked if they wanted to cut some fabric, if they could use my "sewing scissors".
Since you mentioned you had children I would highly recommend one other thing. I would purchase a hand held magnet wand, to keep pins picked up. But,be sure to keep the magnet away from video tapes, computers and your sewing machine if it is an electronic one. A magnet will ruin them.
Someone mentioned Quilter's Cache for free patterns, also a couple of other sites are allpeoplequilt.com. and Connecting Threads.com both have a lot of free patterns as well.
Sorry this is so long.This board is the most helpful place I have ever found!!! and everyone is so willing to share and help everyone with any problem. BIG PATS on BACKS to all on the Board!!!!