Many user interface and interaction design experts will tell you that you should not ask users to make choices when they don't have to. Unnecessary choices presented to the user are the sign of laziness on the part of the development team and ultimately work to the detriment of a user's experience in your application. As a result, it's also extremely important to choose good default values for any choices you do ask users to make. This applies to not only things like "Create New..." tasks, but also to things like search. Let me give you two examples from my own development projects.
First up is a wiki tool we built for our online course system. Everyone's used wikis, right? Wrong. A Pew report from 2007 indicated that less than 15% of all surveyed users (and their survey size is around 2000 people, from which they extrapolate the activities of most US citizens) had a blog, or created a Web page, or posted to a blog. I know that a blog is not a wiki, but the reality is that blog usage is generally considered higher than wiki usage from a content contribution perspective. (The percentage of US citizens who have used Wikipedia is probably a whole lot higher than 15%).
Anyway, the point is this: most of our users weren't familiar with what a wiki was or what they could do with the tool. We provided a simple editing interface, thorough help documentation, and even Flash-based demonstrations of how to use the tool — all accessible from within the wiki interface. That wasn't enough. Users still didn't know what to do with the page by just looking at it. Here's what it looked like to them:

A big white space isn't the most inviting of interfaces to get users started creating content. Robert Hokeman, Jr., makes a strong case for this in his excellent book "Designing the Obvious:"
For users just getting to know a Web application, a blank slate can be a barrier in the learning process. Instead of knowing what to do first, users can become stalled when faced with the empty canvas.
By providing a sample of content or automatically selecting a "getting started" template, users can see what they might be able to build with the tool, or can start clicking and editing what's provided. They don't have to do a lot of figuring out how the tool might be used — you're doing that for them, saving them time and confusion in the process. (Of course, you're also proscribing how the tool can/should be used to them, which can be a detriment to creativity. Creative users, however, will find a way to bend the tool to their own ends. They always do.)
So we went back to the wiki tool and addressed the number one question users had: "I'm not sure what I can do with this thing." By displaying a default preview of what a wiki page could look like, rather than presenting them with a blank screen (or a screen with a tiny bit of text that says "Insert text here" on it), we give the users ideas on how to get started and what, specifically, the tool is designed to do. The updated default view of a wiki page now looks like this:

That's a heck of a lot clearer.
The second example starts to cross in to the realm of instructive design: that is, providing tips and context and the right kind of default values so that the user knows what they are supposed to do with the application, registration form, etc.
Everyone's had the very annoying experience of filling out a form and entering something like a phone number, only to have the system come back to you once you've clicked the "Submit" button and say "Phone numbers must be in the (xxx) xxx-xxxx format." or something equally annoying. A well-designed form that wants to be instructive and help the user enter information in the expected way from the start would pre-populate that phone number field with (xxx) xxx-xxxx so that you could click on it, and start typing in the right format.
In building a survey tool, we decided that a Likert scale question (or matrix question) would be one of the supported question types. The tricky part with supporting that question is getting users to enter in the appropriate setup information for the question. A Likert scale question can be represented by a series of columns (which are the evaluative scale, such as "Excellent, Good, Fair, Poor") and a series of rows (which are the items to be evaluated, such as "Checkout time, Cashier friendliness" and so on).
This was our original design:

Most users could figure out how we wanted the information required using this form. However, we'd still get users who would put all choices on a single line, or separate them using commas or tabs. How to make it clearer? Here's a recent revision:

This is better, as it tells the user exactly what to enter and where to enter it. The design is being instructive. We've provided "defaults" which tell the user what they need to know, and save them from guessing, or confusion about what to put in each of the fields.
We could go farther, however, and create a dynamic preview of the question as the user entered both rows and columns to make up the matrix/Likert question. That's something we're looking into. (There's debate on the value of that, as once a user makes a couple of matrix questions, they pretty much get how to do it and don't need to see a whole lot of other stuff cluttering up the interface.)
So the point here is this: choose good defaults, and make them instructive. The more unobtrusive guidance you can give to your users, the faster they'll get up to speed with your application, and the less (wrong) decisions they'll make in the process.