A quick Google will reveal many sites which indicate best practices. I would say only two things - don't EVER use spaces "My Table Name" (porting becomes impossible due to different escaping mechanisms; same goes for any non-alphanumeric character). With these sorts of mechanims, you normally have to respect case also. There are enough letters and words in the English (or your own) language and identifier lengths are long enough (I don't know any system that has identifier_length < 32, PostgreSQL is 64). And never use SQL keywords (which vary by RDBMS) which will do the same thing.
SELECT "Field" FROM "Table";
can be valid! The absolutely critical thing is to have a clear and relatively simple convention and then stick to it. People have differing opinions as you will find out - read around the topic and pick what "feels right" to you. See these sites 1, 2, 3, 4, 5,... (there are many more).