The first bag I made was from the video below. I loved watching Bobby and thought she did a bang up job of her very first video tutorial. From there, I did make a few changes in that I didn't use squares and chose to either use all one fabric or use a bottom piece of a darker colour just for the sake of setting the bag down on less than clean surfaces. If you follow Bobby's tutorial, you can't go wrong. And, for those who have never made a bag, this is a great starting place.
I will mention though that I did use fuse-able fleece on the bag just as she did and I also used a fairly heavy iron on interfacing on the lining pieces as well. Inserting a zip pocket will require stabilizer. The slip pockets I made to my own measurements. Measure the width of the bag and decide how many pockets you need. I think its best to interface one piece of the fabric here as well. I sewed 2 pieces together - turned, pressed well and sewed to one side of the lining- measured my phone etc and sewed each section making sure to secure stitches well to allow for pulling and tugging. The bag is quite sturdy, but I felt it still needed more stabilizer in the bottom so I covered a piece of vinyl I cut to the measurement required to the size of the bag. I purchased for $5 (enough for several bags)a long piece of vinyl at the builders shop that is really meant for covering gutters so leaves don't clog them. It works like a hot darn and is fairly easy to cut with heavy duty shears.
At this point I should also mention that it took me a bag or two to get into modifying my own requirement for a handy bag. The inside zip pocket is placed on the other lining side. Basically, I used the following two tutorials and then went from there. I would not make a good teacher, so I hope I haven't confused the heck out of anyone interested in making a similar bag.
http://www.youtube.com/watch?v=h00B8af3xNc
http://www.sewmamasew.com/2007/07/tu...cket-tutorial/