Hi Sheila

I think it depends of what you are working on, if it is a short manuscript with a few references, you can generate the list of references manually easily, but if you are working on a big manuscript with hundreds of references, then I would certainly recommend using a reference manager.

I am compiling my thesis at the moment and it is useful to see how the reference manager generates the list of references as I go along. 

I have used refworks because that is the one that is endorsed by my university and they provided free training. However, I have had some problems with it, like sometimes it stops working, I had to re-install it a couple of times etc and I know that once I stop being a student I will have to migrate all my references to another software manager or I will loose them.

I'm sure all the reference managers will have their little problems though!

There are a few free software managers out there, with the advantage that when you move jobs/finish studies etc. you don't have to worry about loosing your references.

I have seen some demos and heard very good things about Zotero, you can save the paper, add notes to it, and even put tags on your papers so you can put your notes as you read the paper, tag it with the key words that will help you remember key details about this paper and then, when you are writing/editing a particular section months later, you can search for tags and all the papers linked to that tag will come up on your screen. Making the process of reading and writing easier. On the contrary, refworks doesn't have the facility of making tags, you would need to make a file for each theme instead.

If you have never used a reference manager, I would suggest you check with your university which one they are subscribed to, and see if they can offer you some training. You will need to learn how to cite in the text using the reference manager, so your citations are effective and correspond to your list of references at the end. Once you have learnt the basic principles, you can then move to other reference managers as they all work similarly.

Here you have  a list of the main reference managers with links to all of them

Best wishes

Lucia