Can you recommend any reads/webpages that elaborates when and what estimator to use in random effects model when conducting a meta-analysis?
The documentation for the metafor() package (Viechtbauer, 2010) in R provides some good suggestions, as metafor() includes 9 different methods of estimating random-effects models. Viechtbauer recommends the references below as good sources for getting up to speed on the ins-and-outs of each estimator, and I've updated to include the references recommended by the commenters below. I would start with Veroniki et al. (2016; open-access).
DerSimonian, R., & Kacker, R. (2007). Random-effects model for meta-analysis of clinical trials: An update. Contemporary Clinical Trials, 28, 105–114.
Langan, D., Higgins, J., & Simmonds, M. (2017). Comparative performance of heterogeneity variance estimators in meta‐analysis: a review of simulation studies. Research Synthesis Methods, 8(2), 181-198.
Raudenbush, S. W. (2009). Analyzing effect sizes: Random effects models. In H. Cooper, L. V. Hedges, & J. C. Valentine (Eds.), The handbook of research synthesis and meta-analysis (2nd ed., pp. 295–315). New York: Russell Sage Foundation.
Veroniki, A. A., Jackson, D., Viechtbauer, W., Bender, R., Bowden, J., Knapp, G., ... & Salanti, G. (2016). Methods to estimate the between‐study variance and its uncertainty in meta‐analysis. Research Synthesis Methods, 7(1), 55-79.
Viechtbauer, W. (2005). Bias and efficiency of meta-analytic variance estimators in the random- effects model. Journal of Educational and Behavioral Statistics, 30, 261–293.
Viechtbauer, W. (2010). Conducting meta-analyses in R with the metafor package. Journal of Statistical Software, 36(3), 1-48. URL: http://www.jstatsoft.org/v36/i03/
Viechtbauer, W., López-López, J. A., Sánchez-Meca, J., & Marín-Martínez, F. (2015). A comparison of procedures to test for moderators in mixed-effects meta-regression models. Psychological Methods, 20, 360–374.