i am going to use cad2010 , can you give advise ?   thanks

Jump in with both feet, and eyes wide open. Make mistakes but learn from them. Are you new to drafting and design? Are you new to AutoCAD period?
If so, learn the shortcut keys, at least for commands. Beginners use point-and-click button commands, but as you gain experience you tend to move toward typing shorthand commands in  conjunction with mouse-clicking. The spacebar works like the <enter> key. C means circle, L means line, etc. PL means polyline, PE means edit polyline.
CAD programs treat the model you draw in modelspace, as if it was being created in a 1:1 scale ratio. Paperspace is for printing (plotting) the output, and is also in a 1:1 scale. Views of your model are arranged in paperspace, which is like the sheet of paper that draftspersons used to draw on, on a drawing board. The views are like monitors looking at a stage, and your model is the object on the stage. You scale the views as if you were zooming the cameras in and out. This is instead of trying to draw the model to a fraction of it's true size (the old fashioned way we used to draw on the board).
It is important these days to have some idea ahead of time what scale and what unit of measurement you will use the most on a particular model. AutoCAD should be set up to draw either imperial or metric, and even in modelspace there is a place to set what scale you want to insert annotative objects into the drawing at.
DDE = direct distance entry. You start a line for example, move your cursor in the direction you want the line to go, then type in the distance and hit enter.
F8 toggles your ortho on and off; F9 the snap spacing; F10 the polar settings (I keep mine at multiples of 15 degrees); F7 your grid (drawing aid); F3 your object snap; F2 your text window; and F1 the help screen.
Ortho is the AutoCAD equivalent of a set square and t square. Polar is like having an adjustable set square. The delete key is like the erase button (if the noun-verb settings are set for that).
That should be enough to get you started. Good luck!

I started learnining Autocad from release 14, and hat no tablet.
So i HAD to learn it all by Keyboard.
I must say that i am very glad i know almost all shortkey commands, it make every thing goes much faster.
 
Other tips :)
- SAVE YOUR DRAWING OFTEN hehehe
- Make a library and save parts you drawn, saves time if you need that same part again.
- Make sure you have FUN making drawings, if you dont have fun with it, you should stop.

[QUOTE=Modman_4]Jump in with both feet, and eyes wide open. Make mistakes but learn from them. Are you new to drafting and design? Are you new to AutoCAD period?
If so, learn the shortcut keys, at least for commands. Beginners use point-and-click button commands, but as you gain experience you tend to move toward typing shorthand commands in  conjunction with mouse-clicking. The spacebar works like the <enter> key. C means circle, L means line, etc. PL means polyline, PE means edit polyline.
CAD programs treat the model you draw in modelspace, as if it was being created in a 1:1 scale ratio. Paperspace is for printing (plotting) the output, and is also in a 1:1 scale. Views of your model are arranged in paperspace, which is like the sheet of paper that draftspersons used to draw on, on a drawing board. The views are like monitors looking at a stage, and your model is the object on the stage. You scale the views as if you were zooming the cameras in and out. This is instead of trying to draw the model to a fraction of it's true size (the old fashioned way we used to draw on the board).
It is important these days to have some idea ahead of time what scale and what unit of measurement you will use the most on a particular model. AutoCAD should be set up to draw either imperial or metric, and even in modelspace there is a place to set what scale you want to insert annotative objects into the drawing at.
DDE = direct distance entry. You start a line for example, move your cursor in the direction you want the line to go, then type in the distance and hit enter.
F8 toggles your ortho on and off; F9 the snap spacing; F10 the polar settings (I keep mine at multiples of 15 degrees); F7 your grid (drawing aid); F3 your object snap; F2 your text window; and F1 the help screen.
Ortho is the AutoCAD equivalent of a set square and t square. Polar is like having an adjustable set square. The delete key is like the erase button (if the noun-verb settings are set for that).
That should be enough to get you started. Good luck! [/QUOTE]

 I have used cad2008 about 2y,some command which i used usually,etc line circle copy move ..... usually the shortut it is just first number of the comand word,it is wonderfull ,faster , i expect the cac2010 nicer than  cad2008, someone tell me the cad2010 is parameter manage ,i think it maybe nice,can you tell me ,what is the defferent between the 2 revision?
thanks

 thanks for you tips
 your attitude is very good ,fun ,
good ,

2009 AutoCAD is worlds different than 2008, because of this new "Ribbon" thing (2010 is essentially the same in appearance). If you used the Dashboards in 2008, the Ribbons take their place, and can be docked to the side like the Dashboard.
Initially, you'll be asking where everything you knew went to, but your settings can be migrated from 2008, and you can set it up to behave like 2008. One thing that shocked me was no longer having a menu across the top, but it can be brought back with a simple command.
 
In short, it's scary at first, but you can make 2010 more like 2008 and then look into all of the improvements/enhancements at your own pace. Good luck!