Hi Lovelosing. and GREAT JOB on your weightloss so far. We have very similar stats. I know how hard it is to carry and lose weight at 62 inches in height.
I'm so glad you are enjoying the free weights. It's my first love too and honestly, nothing else has been nearly as effective as picking up big heavy things and putting them back down again.
It is certainly okay to learn new things. You must continue to learn and incorporate them in order to prevent boredom, injury, and well just stagnation in your development/progress.
Generally, people may put together a program and change it every four to six weeks. This is the period of time in which it is thought the body has made the proper adaptations to the demands that the exercise is placing upon the body. Some people choose to do something completely different every single day they walk into the gym.
Some guidelines though: Make certain that you either do a full body workout every other day (upper and lower together) or a split where you focus upon only upper one day and lower the next. The reason for this is that your muscles need 48 hours to repair from the microtraumas you have created during your lifting efforts.
You will also see the most benefit from lifting weights that are challenging in weight to you at an 8 to 12 rep range. A range greater than this will be a waste of your time in the gym.
Be certain you are using the best form possible and keep your mind in the muscle you are using. Breathe during the lift and exhale during the down phase of the lift to keep oxygen in the muscles as well.
Eat! Eat a good source of protein and carbs (whole grain) within the first two hours of ending your session. Preferably within the first hour but I know sometimes that can be a challenge.
Here are some of my favorite sites from my early learning days:
http://www.stumptuous.com/
http://www.exrx.net/
Another great book many of us have enjoyed is the New Rules of Lifting for Women. You may want to check your library to see if it is available for ideas. I did purchase it when it was published and the spine is broken now. So, if you really enjoy I can endorse it as a decent investment for suggestions.
Happy learning.
Dixied: I love your new avatar. What a nice smile!