Learn about excel functions, arguments, constants etc
1) Use the excel help file - for example, searching for * in the help file takes you to the page for "Calculation operators in formulas" (Admittedly there is no entry for $, but take a look at the entry for 'About cell and range references').
2) Keep browsing here
3) Ask & you shall receive - if you're not clear about something, ask a specific question about it.
4) Look elsewhere on-line for further info. One place that might help you is here:
Has links to other sources of info, but most importantly it has an 'excel function dictionary' you can download. The file lists all the functions in excel & gives working examples. Admittedly less info than the help files, but really good to see the functions 'in action' as it were.