Read the lab manual. Are you in a university? If so, google online and you find find resources pertaining to the exact lab you're supposed to do. If you don't find any, you can try and contact some seniors who may be willing to sell you their previous lab notes.
Textbooks don't help much with labs in my experience, just read the lab manual and google everything you don't understand (which will be quite a lot if this is your first university lab, but no need to get discouraged, the gap in knowledge is normal for everyone
).
Prepare the following before going into lab:
1. know all the safety info about every substance you're expected to use and how to handle them. Eg. Fume hood/no fume hood, keep away from heat, do not inhale, cleaning up procedure, liquid/solid/gas, colour, odour, etc. You can use the Merck index for this which you'll probably find accessible from your university's library page using your student ID.
2. know all that you need to do in the lab. Details are very important here because one screw up and you need to redo the section, this costs you time and you may not get the results you need for your report. So write down what you need to do in ways you understand, highlight all the important parts so that you can look at your sheet and move right on to the next step during lab. You don't want to have to read the manual during lab, takes forever. Remember, details! One knob can screw you up!
3. Bring everything you need to the lab: hairties, gloves, goggles, closed toed shoes, lab coats. Nothing worse than being kicked out.
Good luck. I know this probably sounds intimidating, but that's how it was for me and I finished with 90+ for my course.
If you're not in university but in other types of school, I may be able to help with that, too.
Textbooks don't help much with labs in my experience, just read the lab manual and google everything you don't understand (which will be quite a lot if this is your first university lab, but no need to get discouraged, the gap in knowledge is normal for everyone

Prepare the following before going into lab:
1. know all the safety info about every substance you're expected to use and how to handle them. Eg. Fume hood/no fume hood, keep away from heat, do not inhale, cleaning up procedure, liquid/solid/gas, colour, odour, etc. You can use the Merck index for this which you'll probably find accessible from your university's library page using your student ID.
2. know all that you need to do in the lab. Details are very important here because one screw up and you need to redo the section, this costs you time and you may not get the results you need for your report. So write down what you need to do in ways you understand, highlight all the important parts so that you can look at your sheet and move right on to the next step during lab. You don't want to have to read the manual during lab, takes forever. Remember, details! One knob can screw you up!
3. Bring everything you need to the lab: hairties, gloves, goggles, closed toed shoes, lab coats. Nothing worse than being kicked out.

If you're not in university but in other types of school, I may be able to help with that, too.