I have the book, "Beginning Java Programming". After getting into policy 
files, etc., I then bought the book "Professional Java Security" which 
explained these issues. First, there are 2 places to change the 
java.security file in the security directory in Java - one is Java Runtime 
under the C:\Program Files\Java\j2re1.4.0\lib\security and the second is 
in the in the SDK directory (on mine, D:\JDK14\jre\lib\security). Second, 
FYI: the RMIREGISTRY program is started in the directory at the package 
level, not the .class file level. 
I hope this helps. I have about 15 Wrox books. They are all excellent 
except for the "Professional Java Programming". This book assumes that you 
know everything about Java, inside and out, and gives you a quick look at 
the methods to jog the memory. Plan on the reading the "Professional Java 
Security" book. It is heavy, about 400 pages, but it is worth it. Also, 
get the "Beginning Java Programming" and "Professional Java Programming" 
books. These 3 books will give you a good base. I know how you feel - it 
is frustrating. I felt the same way. But what I found was I had to keep 
looking in other books for answers. 
Final note: Writing skills are extremely poor these days. It is a struggle 
to read books that are poorly written. In the beginning, I had to read 4 
Java books before I came across the Wrox book, "Beginning Java 
Programming" by Horton. I have not read a well written reference book 
since the Bentley Press book, "Engineering and Design of Engines" by 
Arthur W. Judge, published in 1966. (The title may not be exact).) It is a 
shame to struggle. I purchased a book from Amazon with 5 star ratings all 
over the place. It was "Developing Software with UML". It was the worst 
book I have ever read. I read it again to see if it was me. Now I am 
absolutely sure that this Addison-Wesley book sucks. I have never bought 
an AW book again. It seems that the editing staff does a very good job 
compared to other publishers, so stay with them.