thanks everyone there's alot of nice suggestions here and i will be trying them , many many thanks to you all
HUGS DORA

Just remember, there were beautiful quilts created long before anyone had fancy square up rulers. :D

Sharon Schamber has several very helpful videos on how to "true up" blocks to size using spray starch and an iron. Here are links to a couple:

http://www.youtube.com/watch?v=i6aplw_tVZc
http://www.youtube.com/watch?v=sQkF02vpVuw

Tru. I think you must have been a Boy Scout in another life! My dh has been active in BSA for 66 years and he can cook, clean and make anything out of wood.

DO you have two rectangular rulers? Lay the one along one edge of the block and butt the other one across the top of the block, butting the rulers together. You can see if your block is off. It takes a little more time, but you can get there.

If you have a piece of template plastic, you can use it also along with a standard ruler.

You can cut a square (the size you need) out of a piece of freezer paper or card board. Those can be used to check for size and then use the standard ruler to trim.

I used my husband's carpenter square for the first couple of quilts I made. Otherwise I'd go with making a square on paper and tracing around it. I like to have diagonal lines to get the corners straight. You could do this by folding on the diagonal twice. Then you have a center mark and the corner diagonals to line up with your square. Hope this makes sense.

Cereal boxes have great square corners to start with. Measure, measure, measure, then cut! Most older quilts were made with cardboard templates!
Picture frames that have plexiglass are good sources. Another source it to go to your local hardware store and ask for a scrap of plexiglass. If you are really nice, the guy may even cut it square for you! They have good measuring tools! Just decide on the size you want and ask! The worst they can say is "No!"

For templates, I use cardboard, styrofoam meat trays, the plastic in bacon packages, all cleaned thoroughly of course.