To capitalize on ways to make extra income you can (and should) use the Internet for test marketing:

(a) To establish demand for your extra income idea.

(b) To prepare yourself to take advantage of other ways to make extra income i.e. developing a residual income stream.

Unless your first work is of outstanding merit and focused on an equally exceptional topic you will almost certainly require to cool your heels for a spell while your proposal for publication is being assessed for viability.

It could be several months before you receive a decision and with good reason; publishers assume 100% of the financial risk involved and so need to be 100% convinced that your writing-for-profit text is sellable before committing to the first round of expenditure.

Cooling your heels however does not mean to imply that you sit around doing nothing - not if you want to make money writing from the outset.

In this fallow period you ought to be concentrating your energies on some test marketing for your extra income idea book and there is no smarter or efficient way of accomplishing this than using the Internet. Do some engine searching (use google.com for fast results) to locate online publishers specializing in niche non-fiction.

Choose the one whose featured produce most closely meets the criteria of your own area of expertise and make sure that submission of your manuscript won