UNIX for Dummies Questions & Answers

Hi Unix gurus,

I know these are some easy questions.
But i just want to be sure about them.
Hope someone can help explain the following please?

1) if [[ -r /etc/ngtpath.conf ]]
- What does the "-r" means?
2) isql -U $DBUSER -D $DBNAME -S $DSQUERY -w 1000 -s";" << testfile > $FILE
- What does the -s";" mean and what does the "<<" do?
3) if [[ -s $RPTFILE ]]; then
- May i know what the "-s" option do?

Thanks so much in advance.

1. man test
2. isql Utility
<< sets stdin to data in script up to given keyword, man sh
3. man test