First and foremost, you do not need to restate your entire resume. Anybody reading your cover letter will also have your resume. Second, you do not need to kiss the ass of the reader by saying things like “I know that bank XYZ has the smartest people, most dealflow and is the coolest place to work!” If you have a concrete reason why you want to work at that bank then yes, say so (in ONE sentence) but if you go too far, you come off sounding naive. After all, for the most part banks (at least bulge brackets) are pretty much the same.
Third, don’t go overboard stating how great you are. Just about everyone applying to investment banking is “smart,” “hardworking,” “enthusiastic,” etc. The reader will judge these traits by your resume (where you went to school, degrees, GPAs, test scores, prior work experience/internships, etc.). Finally, don’t say how the firm is going to benefit by letting you work there. To them, you are just one more potential Analyst or Associate. That is to say, you are a commodity. No Analyst or Associate that is new to banking is going to be able to contribute significantly for months, so to state otherwise makes you once again seem naive.
First, few people (in investment banking) read cover letters. You are going to get judged almost exclusively on your resume. And generally, the only time a cover letter will have an impact on your chances is if you say something stupid or have typos. That is to say, cover letters (or cover emails) are usually necessary but are likely to hurt you more than help you. So since (1) few people read them and (2) they are more likely to hurt you, you might as well keep them short and to the point.
Unless a job posting explicitly requires you to send a cover letter (which is rare), then no, you do not need a separate cover letter when emailing about a job. Just let the email be your cover letter. And keep the email short!
I’m a big fan of SHORT cover letters. Basically, in one sentence, state the job you are applying for or how you heard about it. Mention that you’ve enclosed/attached your resume. Then in not more than 2-3 sentences mention some relevant facts about yourself. Lastly, thank them and tell them how they can reach you or that you will follow up. That’s it.
Resumes should not be longer than one page. For other industries, multi-page resumes are acceptable, but for investment banking, PLEASE keep it to one page. In addition to the resume, experienced bankers should have a list of transactions that can run one or more additional pages.
My personal view on a resume section for interests is that it can hurt you more than it can help you. Yes, if your passion is medieval Icelandic art, and it just so happens that your interviewer also loves medieval Icelandic art, then it probably helps. But those instances are pretty darn rare. If you do need to fill up some space on your resume (e.g. if you are still in undergrad) and your interests are “interesting” then put them on your resume. If you do need more space to fit you resume on one page, this section should be the first thing to be removed.
If you do include interests, whatever you do, make sure than you can speak intelligently about them in an interview because someone will ask. For example, if you list reading as an interest, make sure to have a few books (not Harry Potter) that you can speak about that you’ve read recently.
My general view on skills is that if they are relevant and/or interesting then yes, include them at the bottom of your resume. However, if you need more space to fit your resume on one page, skills are one of the first things that should go. Language skills especially (except Latin) should be included as they might actually one day be relevant to your banking job. Computer skills are okay to list if they include REAL computer skills (e.g. programming languages) but PLEASE don’t list Microsoft Word, Excel, Outlook etc. as a skill. It’s pretty much assumed in today’s world that if you can speak English and have half a brain, then you are familiar with Microsoft Office!
If you are still in school or a couple of years out of school, and your test scores are very good (i.e. 700 or above for GMATs, ??? for SATs), then, yes it is okay to include your test scores. In fact, some people may assume that if you do not include your test scores, then you scored below these thresholds. However, once you are more than a couple of years out of school, I personally think it is tacky to include test scores, regardless of how high you scored.
As with standardized test scores, if your GPA is very good (generally 3.5 is considered the threshold) and have graduated within the last few years, then you should include your GPA. If you are applying to Analyst jobs while still in undergrad, you probably should put your GPA on you resume regardless, unless it is really bad (if you don’t include it, readers may assume it is really bad). If your GPA in your major was better than your overall GPA, then include that too.