The Cochrane Handbook isn't set down to be a standard, but it has become the de facto standard for planning and carrying out a systematic review. Chapter 6, Searching for Studies, is most helpful in planning your review.
AHRQ Methods Guide for Effectiveness and Comparative Effectiveness Reviews
Very good chapters on conducting a review, most of which were published as articles in the Journal of Clincal Epidemiology. For searching see especially Finding Evidence for Comparing Medical Interventions and Selecting Observational Studies for Comparing Medical Interventions.
Systematic Reviews: CRD's Guidance for Undertaking Reviews in Health Care
Provides a succinct outline for carrying out systematic reviews and well as details about constructing a protocol, testing for bias, and other aspects of the review process. Includes examples.
Systematic reviews to support evidence-based medicine how to review and apply findings of healthcare research
http://nrs.harvard.edu/urn-3:hul.ebook:GEN_329666 (Harvard ID required)
Khan, K., & Royal Society of Medicine. 2nd ed, 2013. London [England]: Hodder Annold.
Systematic reviews to answer health care questions
Nelson, H. (2014). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.
You will improve the quality of your review by adhering to the standards below. Using the approriate standard can reassure editors and reviewers that you have consciencously carred out your reveiw.
Institutes of Medicine Standards for Systematic Reviews
The IOM standards promote objective, transparent, and scientifically valid systematic reviews. They address the entire systematic review process, from locating, screening, and selecting studies for the review, to synthesizing the findings (including meta-analysis) and assessing the overall quality of the body of evidence, to producing the final review report.
Consider using PRISMA-P when completing your protocol. PRISMA-P is a 17-item checklist for elements considered essential in protocol for a systematic review or meta-analysis. The documentation contains an excellent rationale for completing a protocol, too.
Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009 Jul 21;6(7):e1000097. Epub 2009 Jul 21. PubMed
Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, Clarke M, Devereaux PJ, Kleijnen J, Moher D. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. PLoS Med. 2009 Jul 21;6(7):e1000100. Epub 2009 Jul 21. PubMed
Shamseer L, Moher D, Clarke M, Ghersi D, Liberati A, Petticrew M, Shekelle P, Stewart LA; PRISMA-P Group. Preferred reporting items for systematic review andmeta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ. 2015 Jan 2;349:g7647. doi: 10.1136/bmj.g7647. PubMed PMID: 25555855.
Moher D, Shamseer L, Clarke M, Ghersi D, Liberati A, Petticrew M, Shekelle P, Stewart LA; PRISMA-P Group. Preferred reporting items for systematic review andmeta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev. 2015 Jan 1;4:1. doi: 10.1186/2046-4053-4-1. PubMed PMID: 25554246.
Also published in the Annals of Internal Medicine, BMJ, and the Journal of Clinical Epidemiology.
Meta-analysis of Observational Studies in Epidemiology checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology. Editors will expect you to follow and cite this checklist. It refers to the Newcastle-Ottawa Scale for assessing the quality of non-randomized studies, a method of rating each observational study in your meta-analysis.
Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA, Thacker SB. Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA. 2000 Apr 19;283(15):2008-12. PubMed PMID: 10789670.