I'm not sure whether you are looking for design advice of advice about packages and classes that are likely to be useful.
In my experience, most "business report" documents seem to have the following features (compared to "standard" LaTeX documents):
The textblock is relatively wide (in other words, margins are smaller).
The font used is not Computer Modern.
Headings are important for document structure, and are often set in a contrasting font from the text.
Paragraphs are generally separated with whitespace rather than indentation, and are not infrequently numbered.
Extensive use is made of bullet points and other aids to scanning documents quickly.
In terms of "general" document layout (e.g. the width of the margins) the standard document classes don't look much like "business reports" of the sort generated by Word and the like. If you think that's a bad thing, you might like to look at alternative document classes. The KOMA-script bundle is a pretty good place to start. The tufte bundle offers an interesting alternative approach; again, distinctive -- but practical and elegant. If you prefer to "roll your own" by resetting margins and so forth, do yourself a favour and avoid even thinking about setting lengths: the packages geometry (to set margins) and setspace (to set line spaces) are where you should start.
For some reason, the consumers of business documents tend to be chary of hyphenation. There are very good reasons to prefer hyphenated over non-hyphenated text, especially if your text is justified. But if you want to avoid it, consider ragged right text, for which either the (extreme) solution of
\raggedright or the more nuanced opportunities offered by ragged2e present possibilities. (And, IIRC, the tufte class for instance uses ragged right in any event.)
Computer Modern is distinctive; it's not to everyone's taste, and it certainly stands out. Unless your document contains significant amounts of mathematics (in which case you are practically constrained by the need to find matching fonts with all the necessary characters required for mathematical work), you will probably want to use different fonts. There's a variety of options here -- some packages which set alternative fonts (such as mathptmx or newtx for Times), or a general solution like fontspec which will let you use a much wider variety of fonts that are installed on your computer.
If you are working for yourself, and serious about creating a "brand identity", a careful and distinctive choice of font is a good way to go. Though not everyone would agree, if slick presentation is important for you, it's sensible to consider buying a properly equipped font; it won't cost a fortune. (If you object to buying fonts when you can get them free, remember that there are people (not me!) whose living depends on designing fonts, and who are really expert at it.)
The standard classes' approach to headings are probably not typical of business documents, where it is quite common to find different ways of identifying headings (such as contrasting typeface). Setting up headings is always surprisingly complex--there's more to think about than you would suppose); a class like the KOMA-script classes can help, or use a package like titlesec.
One characteristic feature of business documents is that they use "spaced" rather than indented paragraphs. If you are using KOMA-script, for instance, it has this facility built in as an option (look up "parskip" in the documentation); if you are "rolling your own" consider the parskip package, which deals with various complexities for you.
Another common feature of business reports is numbered paragraphs. I don't know of any truly satisfactory package for this. There's some very sound advice in this answer.
Bullets and Lists
Business reports often make very extensive use of bullets and similar lists. The enumitem package is a very convenient way of handling these.
For tables, the booktabs package is essential -- and still more essential is to read its documentation which will show you how to produce professional looking tables and why many of the tables you see are bad.
A Big Fat Warning
In considering all this, do bear in mind that there may well be a tension between the familiar and the good. Lots of things that make documents look "conventional" may not be good things at all. The "business report" is a mishmash of hangovers from old technology (the typewriter) and opportunities offered by new technology, often misused. Do ask yourself whether the choices you are making are good. Try to look at examples of properly designed business reports (e.g. annual reports), and don't get too hung-up about making your document resemble those that others produce using the sometimes bad default settings of widely-distributed word-processing software.
For general advice on typography, Bringhurst's Elements is the modern classic. Online, there is sound advice (free!) in the documentation for the memoir class, and (not just for lawyers) at the Typography for Lawyers website.